NH4NO3 Solution Research Articles

Mechanical properties of eco-friendly cements-based glass powder in aggressive medium

Recycling glass waste for developing sustainable cementitious mortar and concrete have recently attracted increasing attentions for the construction industry. From another aspect, the nitrate-based environment due to chemical fertilizers has a significant effect on reinforced concrete and normal concrete by producing damages like its microstructure, corrosion of reinforcement. The major goal of this research work is to study the effect of Ammonium Nitrate (NH4NO3) on the unite weight and strength of glass mortar by performing experimental tests. In this article, eco-friendly mortar containing recycled glass powder (GP), as a replacement to cement, is submerged in NH4NO3 solutions. In total, 60 cement mortar mixtures were proportioned in this research work used GP passing sieves 200 µm. NH4NO3 solutions with 5, 10, and 20% concentration, and three different exposure periods 10, 30, and 60 days were applied. The experimental results showed that the effect of NH4NO3 on the density of mortar containing GP is less critical than that of conventional mortar. After 60 days of immersion in the solution with a concentration of 20% NH4NO3, the reduction in density of glassy mortar is less than that of ordinary mortar. Furthermore, the results indicated that the maximum compressive strength was attained at 10% replacement level of cement with GP by approximately 60 MPa after 60 days of immersion in NH4NO3 solution.

Enhanced Reactivity of Accessible Protons in Sodalite Cages of Faujasite Zeolite

AbstractFaujasite (FAU) zeolites (with Si/Al ratio of ca. 1.7) undergo mild dealumination at moderate ion exchange conditions (0.01 to 0.6 M of NH4NO3 solutions) resulting in protons circumscribed by sodalite cages becoming accessible for reaction without conspicuous changes to bulk crystallinity. The ratio of protons in sodalite cages (HSOD) to supercages (HSUP) can be systematically manipulated from 0 to ca. 1 by adjusting ammonium concentrations used in ion exchange. The fraction of accessible protons in the sodalite cages is assessed by virtue of infrared spectra for H‐D exchange of deuterated propane based on the band area ratio of OD2620/OD2680 (ODSOD/ODSUP). Protons in sodalite cages (HSOD) show higher rate constants of propane dehydrogenation (kD) and cracking (kC) than protons in supercages (HSUP) plausibly due to confinement effects being more prominent in smaller voids. Rate constants of dehydrogenation and cracking including kD/kC ratios are also augmented as the fraction of accessible protons in the sodalite cages is enhanced. These effects of accessibility and reactivity of protons in sodalite cages hitherto inconspicuous are revealed herein via methods that systematically increase accessibility of cations located in sodalite cages.

Enhanced Reactivity of Accessible Protons in Sodalite Cages of Faujasite Zeolite.

Faujasite (FAU) zeolites (with Si/Al ratio of ca. 1.7) undergo mild dealumination at moderate ion exchange conditions (0.01 to 0.6 M of NH4 NO3 solutions) resulting in protons circumscribed by sodalite cages becoming accessible for reaction without conspicuous changes to bulk crystallinity. The ratio of protons in sodalite cages (HSOD ) to supercages (HSUP ) can be systematically manipulated from 0 to ca. 1 by adjusting ammonium concentrations used in ion exchange. The fraction of accessible protons in the sodalite cages is assessed by virtue of infrared spectra for H-D exchange of deuterated propane based on the band area ratio of OD2620 /OD2680 (ODSOD /ODSUP ). Protons in sodalite cages (HSOD ) show higher rate constants of propane dehydrogenation (kD ) and cracking (kC ) than protons in supercages (HSUP ) plausibly due to confinement effects being more prominent in smaller voids. Rate constants of dehydrogenation and cracking including kD /kC ratios are also augmented as the fraction of accessible protons in the sodalite cages is enhanced. These effects of accessibility and reactivity of protons in sodalite cages hitherto inconspicuous are revealed herein via methods that systematically increase accessibility of cations located in sodalite cages.

Colorimetric detection of polycyclic aromatic hydrocarbons by using gold nanoparticles

The existence and content of polycyclic aromatic hydrocarbons (PAHs) in the environment have gradually received attention because PAHs are widely detected in many sources. Therefore, an effective detection method for PAHs is necessary for further treatment. This study proposes a novel colorimetric detection method based on AuNPs to determine the contents of phenanthrene (Phe) and pyrene (Pyr). Trisodium citrate was used as a reducing agent to synthesize gold nanoparticles, and ammonium nitrate (NH4NO3) was added as a reactant to detect the analyte content. Some assay parameters, such as the concentration of NH4NO3 solution, the volume of NH4NO3 solution, the concentration of MES buffer solution, the volume of MES buffer solution, and the reaction time influenced the analyte detection ability of AuNPs and were optimized. The limits of detection for Phe and Pyr are 0.06 mg/L and 0.087 mg/L, respectively. In addition, the detection method has good selectivity and anti-interference ability for the target analytes. This colorimetric method was used to detect target analytes in real water (tap water and mineral water) with acceptable results.

An investigation of aqueous ammonium nitrate aerosols with soft X-ray spectroscopy

Aqueous aerosols are important in atmospheric chemistry, drug delivery, and human health. X-ray photoelectron spectroscopy (XPS), a surface-sensitive technique and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy which informs on the bulk, is deployed to study the solvation of ammonium nitrate (NH4NO3). Aerosolised solutions of NH4NO3 were introduced into a photoelectron spectrometer via an aerodynamic lens, and interrogated with soft X-ray photons, the resulting electrons were imaged via velocity map imaging. Density functional theory calculations were performed to compare with the measured binding energies of NH4 + and NO3 − solvated in water. The results reveal that the nitrate anion has a slight propensity for the surface, while both ammonium and nitrate ions are present in equal measure in the bulk.

Phase diagrams for the ternary system (NH4NO3 + CsNO3 + H2O) at 298.15 and 348.15 K and its application to cesium nitrate recovery from the eluent aqueous solution of ammonium nitrate

A novel green process for CsNO3 separation from the eluent solution of NH4NO3 was developed based on the predictive phase diagrams of (NH4NO3 + CsNO3 + H2O) at 298.15 and 348.15 K, which were drawn using the Pitzer and its extended HW model. These single-salt parameters and the mixing ion parameters obtained either from the literature or fitted with the relevant experimental data in the literature were used to calculate the solubilities of the ternary system (NH4NO3 + CsNO3 + H2O) at two temperatures successfully. Based on phase diagrams at 298.15 and 348.15 K, a comparison of the ternary system diagrams shows that area of CsNO3 crystallized region is decreased obviously with the increasing temperature, which accounts for separating cesium nitrate from eluent by raising the temperature. Under the guidance of the predictive phase diagram at 298.15 and 348.15 K, the separating process of cesium nitrate from the eluent solution of ammonium nitrate by three fractional crystallization operations was established for the first time, and the material balance of the cyclic process is presented.

Investigating the effects of oxygen enrichment with modified zeolites on the performance and emissions of a diesel engine through experimental and ANN approach

Oxygen enrichment of intake air in internal combustion engines (ICE) is one of the effective methods used to reduce exhaust emissions and increase performance. In this study, oxygen enrichment process was performed with pressure swing adsorption (PSA) method using two zeolite types including acid-modified zeolite (AMZ) and base-modified zeolite (BMZ). In the experiments, clinoptilolite-type natural zeolite in 1.6–3 mm fractions was used. HCI, NH4NO3 and NaOH solutions were used to obtain AMZ and BMZ. Engine experiments were carried out using a four-stroke, single cylinder, direct injection, air-cooled diesel engine. In addition, by designing an artificial neural network (ANN) model with the capability to estimate the experimental results, its performance was tested. When the oxygen rate (21%) in the medium air, where the experiments were carried out, was compared with the oxygen rates in the air obtained with the use of AMZ and BMZ in zeolite filter (ZF) system, an increase of 17.14% and 21.90% was observed, respectively. As a result of the addition of oxygen-enriched air to the fresh air drawn into the combustion chamber in the ZF system, the carbon monoxide (CO), hydrocarbon (HC), smoke density and brake specific fuel consumption (BSFC) values decreased and the nitrogen oxide (NOX), vibration, noise, exhaust gas temperature (EGT) and brake thermal efficiency (BTE) values increased when compared to standard diesel engine (SDE). According to the obtained results, ANN estimated the exhaust emission and performance parameters with the regression values (R) of 0.99423–0.99990 and low error rates in the range of 0.002–6.93%.

Biomineralization of Cd2+ and inhibition on rhizobacterial Cd mobilization function by Bacillus Cereus to improve safety of maize grains

Reducing cadmium (Cd) bioavailability and rhizobacterial Cd mobilization functions in the rhizosphere via the inoculation of screened microbial inoculum is an environmental-friendly strategy to improve safety of crop grains. In this study, Bacillus Cereus, a model Cd resistant strain, was selected to explore its effects on Cd bioavailability and uptake, bacterial metabolic functions related to Cd mobilization. Results indicated that inoculation of Bacillus Cereus in maize roots of sand pot with water-soluble Cd (0.06–0.15 mg/kg) and soil pot with high Cd-contaminated soil (total Cd: 2.33 mg/kg; Cd extracted by NH4NO3: 38.6 μg/kg) could decrease water-soluble Cd ion concentration by 7.7–30.1% and Cd extracted with NH4NO3 solution by 7.8–22.5%, inducing Cd concentrations in maize grains reduced by 10.6–39.9% and 17.4–38.6%, respectively. Even for a single inoculation in soil, Cd concentration in maize grains still satisfy food safety requirements (Cd content: 0.1 mg/kg dry weight) due to its successful colonization on root surface of maize. Bacillus Cereus could enrich more plant growth promotion bacteria (PGPB) and down-regulate the expression of genes related to bacterial motility, membrane transports, carbon and nitrogen metabolism in the rhizosphere soil, decreasing Cd bioavailability in soil. Approximately 80% Cd2+ in media was transferred into intracellular, meanwhile Cd salts (sulfide and/or phosphate) were produced in Bacillus Cereus through biomineralization process. Overall, this study could provide a feasible method for improving safety of maize grains via the inoculation of Bacillus Cereus under Cd pollution.

Influence of silica fume, metakaolin & SBR latex on strength and durability performance of pervious concrete

This study evaluates the performance of pervious concrete subjected to rapid freeze–thaw (F-T) cycling, calcium leaching and the combined attack of calcium leaching and F-T cycling. Silica fume, metakaolin and SBR polymer emulsion were incorporated at different levels into pervious concrete mixes to improve strength and durability performances. The results indicated that the addition of 5% fine sand and proper compaction had a positive influence on improving the resistance of pervious concrete to F-T cycling. The increase of supplementary cementitious materials (SCMs) from 5% to 10% significantly improved the resistance to rapid F-T cycling and to the combined attack of calcium leaching and F-T cycling. The optimum content of SCMs was 10% based on the mechanical and durability performance of pervious concrete with acceptable permeability. Calcium leaching in 6 M NH4NO3 solution combined with F-T cycling induced severe surface deterioration and internal damage compared to individual attacks of F-T cycling or leaching. Compared with control and polymer-modified mixes, pervious concrete incorporated SCMs possessed better resistance of calcium leaching and frost. The morphological changes caused by calcium leaching exhibits the decreased volume fraction of solid phases in a cement matrix and consequently increased the porosity, which ultimately degraded strength and durability performance of pervious concrete.

Pyrolitic conversion of palm oil into liquid fuel using protonated zeolite-X prepared from rice husk silica and aluminum foil as catalyst

Zeolite-X was successfully synthesized based on silica of rice husk and aluminum foil with the variation of sodium silicate aging time of 24, 48, 72, and 96 hours with a crystallization time of 96 hours as evidenced by XRD analysis with a 2θ angle peak diffractogram pattern similar to the IZA standard. Zeolite-X with sodium silicate aging time of 24 hours is the best zeolite-X with XRF analysis with components Na2O 0.436%, Al2O3 33.933%, and SiO2 65.631%, and the SEM surface morphology shape crystal was homogeneous cubes. Protonated zeolite-X or zeolite H-X has been successfully synthesized through the ion exchange process of zeolite-X with 2M NH4NO3 solution which had been proven by XRF analysis to reduce Na2O from 0.436% to 0.179%. Zeolite-X and zeolite H-X have the same 2θ angle diffractogram pattern. In SEM analysis, the surface morphology of zeolite H-X had a formless surface morphology. Zeolite H-X was applied in pyrolysis experiments using palm oil to produce liquid fuel. Liquid fuel was analyzed by GC-MS with components 77% hydrocarbon, 16% acid, and 7% ketones.

Problems Encountered during In vitro Culture Establishment in Terminalia arjuna

The main aim of present study was to overcome the problems associated with the in vitro culture initiation in Terminalia arjuna. The micropropagation of tree species is not easy as shrubs and herbs. Many problems encountered from explant collection to in vitro culture establishment. The problems that have been occurred during T. arjuna micropropagation were culture contamination, phenolic exudation, bud growth inhibition, shoots yellowing and leaf fall. All these problems have been solved by applying certain treatments prior to explant collection and inoculation. The mother tree was lopped in November months (six months prior to explant collection) to remove any inhibitory substance and release bud growth. Different sterilizing agents were used to minimize the bacterial and fungal contamination. Some modification in culture media (use of different concentration of NH4NO3 and KNO3 salts and adenine sulphate) was done. Surface sterilization of nodal explants collected from lopped branches with 0.1% HgCl2 for 8 min., treatment with chilled antioxidant solution (Ascorbic acid, Citric acid and PVP) and half strength of NH4NO3 and KNO3 salts of MS medium supported 100% bud break response with proliferation of green and healthy in vitro shoots. Removing these hurdles already in the initial stage of micropropagation is very important and maximize mass in vitro propagation of this medicinally important Arjun tree.

Effects of Filter-Membrane Materials on Concentrations of Trace Elements in Acidic Solutions

Filtration is commonly used to separate liquids from solid materials before the determination of trace element concentrations in aqueous solutions. Therefore, it is important to determine how much elemental content is extracted from the filter itself or lost via absorption into the filter. In this study, we investigated three types of disposable syringe filters (polyvinylidene difluoride, PVDF; polytetrafluoroethylene, PTFE; PTFE with glass microfiber prefiltration media, GD/X) and their acid-cleaned versions using ammonium nitrate (NH4NO3) and acetic acid (HOAc) solutions. The concentrations of most trace elements (Li, Al, Cr, Mn, Co, Ni, Cu, Zn, Rb, Sr, Mo, Cd, Cs, Ba, Pb, and U) were higher in filtrates that had passed through acid-cleaned filters than those that had passed through uncleaned filters. In filtrates from PVDF and PTFE filters, many trace elements were below the detection limit. However, regardless of the filter type and acid cleaning, Li, Cu, Zn, Mo, and Ba concentrations in filtrates of NH4NO3 solutions, and Al, Cr, Mn, Cu, Zn, and Ba concentrations in filtrates of HOAc solutions were much higher than those of other trace elements. These differences were particularly noticeable in filtrates from GD/X filters containing glass microfiber layers. These data indicate that certain trace elements can be released from membrane materials by reacting with acid in the filtered solution. Furthermore, the amounts of each trace element were associated with the membrane type. These findings suggest that filter type should be carefully selected to obtain the required accuracy, in consideration of the target elements and whether an acid-cleaned filter is needed.

Rapid nitrogen fixation contributes to a similar growth and photosynthetic rate of Robinia pseudoacacia supplied with different levels of nitrogen

Robinia pseudoacacia L. is a legume species that is widely used in afforestation, which has high N2 fixation capacity and rapid growth rate. Both nitrogen (N) supply and phenology affect plant growth, photosynthesis and leaf senescence. The aim of this study was to determine how N supply affects N2 fixation, leaf photosynthesis and senescence of R. pseudoacacia at different phenological stages. Seedlings of R. pseudoacacia were supplied with different levels of 15N-labelled NH4NO3 solution, with seedlings of Sophora japonica Linn. as reference plants to calculate the percentage of N derived from the atmospheric N2 (%Ndfa). Compared with plants supplied with a high N level, those with a low N supply had a higher %Ndfa at an early developmental stage. Nitrogen fixation compensated the effect of a low N supply on plant growth in R. pseudoacacia. A high N supply decreased biomass allocation to lateral roots and nodules, and increased the relative growth rate of plant height as well as specific leaf area. The eighth mature compound leaf of R. pseudoacacia tended to have a higher net photosynthetic rate than the fourth leaf, and the leaves still maintained a moderate photosynthetic rate in early autumn. Plants tended to allocate more biomass to leaves at an early developmental stage and to stems and roots at a later developmental stage (3 months old). The N level did not affect leaf photosynthesis at different phenological stages, primarily due to (i) a high %Ndfa under low N supply at early growing stage, and a similar high %Ndfa under all N supplies at a late growing stage, and (ii) the delayed greening phenotype of expanding leaves to save nutrients for mature leaves.

Electrochemical Separation of Molybdenum and Tungsten Using Aqueous-Organic Electrolytes

Molybdenum is one of the valuable metals for the industry; its special properties make it extremely urgent to study the process of separation of molybdenum from other impurities. The article considers the optimization of electrochemical separation of molybdenum from Mo-W system. The electrochemical dissolution of molybdenum and tungsten in solutions of LiCl and NH4NO3 in dimethylsulfoxide was studied using polarization curves and calculation of the efficiency of anodic dissolution of molybdenum in the presence of tungsten. The electrolyte with a composition of 0.5 M LiCl; 5.2 M dimethylsulfoxide; 32.2 M water was selected as an effective solution for the electrochemical separation of molybdenum in the potential range of 1.0‒2.2 V. Results obtained in this study can be used for the development of selective separation method in the molybdenum production.

Potassium recovery from vinasse by integrated electrodialysis – precipitation process: Effect of the electrolyte solutions

Abstract This study aimed to investigate the influence of four different electrolyte solutions (Na2SO4, MgSO4, K2SO4, and NH4NO3) on electrodialysis (ED) performance for vinasse desalination and nutrient recovery, especially of potassium, for agricultural purposes. The experiments were carried out using a mixed configuration of ion exchange membranes, which utilized a monoselective cationic membrane between the central and cathode concentrated compartments and the other non-monoselective membranes. The solution performance was mainly evaluated in terms of energy efficiency as well as nutrient removal and recovery (Ca2+, K+, and Mg2+). The chemical equilibrium model Visual MINTEQ was used to estimate the struvite and K-struvite precipitation from the cathode concentrated stream. The MgSO4 and NH4NO3 solutions provided the best conditions for vinasse desalting and subsequent nutrient recovery. When MgSO4 and NH4NO3 were used as electrolyte solutions, 4.4 and 3.9 kg of K-struvite and 0 and 7.3 kg of struvite per m3 of treated vinasse were estimated to be produced, respectively. The desalted vinasse, with a lower potassium content, can be applied via fertigation at higher rates. Therefore, ED is a promising alternative method for vinasse treatment, reducing the environmental impacts associated with its disposal. Moreover, the integration of ED with precipitation has great potential to produce valuable fertilizer.

Speciation Analysis of Chromium in Chromium-Enriched Yeast by Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry.

Chromium-enriched yeast (CrY) is a popular Cr dietary supplement, but suitable speciation analysis of highly toxic Cr(VI) in CrY is not available. Ion chromatography-inductively coupled plasma mass spectrometry method was firstly developed and validated for the quantification of Cr(III) and Cr(VI). Ultrasound-assisted weakly alkaline EDTA solution combined with boiling was used to extract two Cr species in CrY. Two species were separated on two successive anion-exchange columns using a mobile phase of 0.6mmol/L EDTA and 76mmol/L NH4NO3 solution. The method was sensitive, accurate (92.4-100.9%), and precise (0.8-3.1%). Species of Cr(VI) were not found in CrY.

Hierarchical H-ZSM-5 zeolite and sulfonic SBA-15: The properties of acidic H and behavior in acetylation and alkylation reactions

A commercial H-ZSM-5 zeolite was modified by alkaline treatment using NaOH solutions in different concentrations, followed by consecutive ion exchanges with NH4NO3 solution in order to recover the acidic form of the material. According to the intensity of the treatment, mesoporosity with pore size ranged between 9 and 13 nm was generated in the zeolite. Also, the strength and number of acid sites were practically maintained, observing only a noticeable decrease for the more intense treatment. After testing in the glycerol acetylation reaction, some improvements in the activity were observed compared to the original zeolite, but no appreciable increment in the selectivity to diacetin (DA) and triacetin (TA) was reached. However, when a mesoporous SBA-15 functionalized with propylsulfonic acid groups was used as catalyst, the selectivities to DA and TA were noticeably enhanced. Moreover, the zeolites were tested in the isobutane/butene alkylation reaction in gas phase, and also in this case the modified materials did not favor the production of trimethylpentanes (TMPs) compared to the original zeolite. Characterization results allowed to conclude that the mesopores formed in the zeolite after the modification facilitated the accessibility of reactants and products to some acid sites, but these have not enough concentration, being most of them located in the micropores of the zeolite. H-D exchange in sulfonic SBA-15 prior to butene pulses demonstrated that its acidic H has not capacity for butenes adsorption. This explains the lack of activity of this catalyst in the isobutane/butene alkylation reaction.

Determination of Cr(VI) in rice using ion chromatography inductively coupled plasma mass spectrometry

Determination of Cr(VI) in rice is reported using ion chromatography (IC) and dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS). Cr(VI) is separated from other Cr species within 4.5 min using NH4NO3 solution at pH 8.8 as mobile phase. Spectral interferences on 52Cr+ are minimized with NH3 in DRC. The detection limit of (LOD) Cr(VI) is 0.06 ng mL−1. This methodology is utilized for the determination of Cr(VI) in different rice samples and can also be applied for screening of rice for toxicity with respect to Cr. The Cr species are leached from rice powder into 5% (v/v) tetramethyl ammonium hydroxide (TMAH) solution in an ultrasonic bath. The extracts are analyzed by IC-DRC-ICP-MS for Cr(VI). Spike recoveries of Cr(VI) are 98–102% and precision between sample replicates is better than 6.3%. No Cr(III) is converted to Cr(VI) during extraction. Cr(VI) is present in all the rice samples analyzed.

Synthesis and physico-chemical characterization of Beta zeolite catalysts: Evaluation of catalytic properties in Prins cyclization of (−)-isopulegol

Abstract Synthesis of Beta zeolite catalysts was carried out using two different methods. The influence of such parameters as synthesis time and temperature, gel composition and gel ripening on the physico-chemical and catalytic properties of Beta zeolite catalysts was studied. A range of analytical methods was applied in this work including scanning and transmission electron microscopies, energy dispersive X-ray spectroscopy, X-ray powder diffraction, nuclear magnetic resonance spectroscopy – 27A1-MAS-NMR and 29Si-MAS-NMR, nitrogen physisorption, Fourier transform infrared spectroscopy and inductively coupled plasma optical emission spectrometry. The sodium forms of Beta zeolites were transformed to the proton forms H-Beta by ion-exchange using aqueous solutions of NH4NO3 and thereafter evaluated in Prins cyclization of (−)-isopulegol with benzaldehyde. The best catalyst synthesized at 150 °C in the rotation mode for 17 h possessing an optimal combination of morphological and structural properties as well as concentration of acid sites demonstrated high (−)-isopulegol conversion (93%) along with high selectivity to the desired product (79%).

Microscopic analysis of the deleterious effects of ammonium nitrate fertilizer on concrete

This paper presents a detailed study of parameters that makes concrete resistant to ammonium nitrate (NH4NO3) fertilizer attack. The major goal of this research work is to study the effect of ammonium nitrate on the strength and microstructure of silica fume (SF) composite concrete by performing microscopic testing techniques. X-ray diffraction (XRD) & Scanning Electron Microscopy (SEM) were used to study the mineral & chemical compositions of deteriorated samples. Cylindrical specimens were prepared by using silica fume as a partial replacement of cement i.e. 0%, 5%, 8%, and 10% in order to fulfill the requirement of impermeability of concrete specimens towards NH4NO3. The results show that compressive strength varies with the variation in SF content. Composite Concrete specimens for all percentages of SF were subjected to a 5% solution of NH4NO3 and its deleterious effect on concrete was accelerated using alternate wetting and oven drying cycles. SEM and XRD results showed the production of calcium nitrate as a product of deterioration. It is concluded that concrete samples with SF content of 8% have shown significant improvement in strength and more resistant to the NH4NO3 attack as compared to the other samples.