Iranian Journal of Chemistry and Chemical Engineering
Volume:41 Issue: 12, Dec 2022

This study investigated the synthesis of Zinc oxide (ZnO) nanoparticles using Syzygium cumini fruit (Indian blackberry) seed extract. The seeds extract of Syzygium cumini fruit have properties of anti-diabetic, anti-inflammatory, and anti-bacterial, and traditionally it has long been used in Indian folklore medicine. Zebrafish embryos and larvae were treated with 5 different concentrations (0, 25, 50, 75, 100, 150 µg/mL ) of Zinc oxide (ZnO) nanoparticles from 4 hours post fertilization (hpf). The results showed that exposure to 50-150 µg/mL zinc oxide nanoparticles (ZnO NPs) induced developmental toxicity in these embryos, causing mortality, hatching delay, and malformation. Exposure of 50-150 µg/mL  Zinc oxide (ZnO) nanoparticles to zebrafish embryo caused coagulated unhatched phenotype, spinal curvature, axis bent, tail malformation, yolk sac, and pericardial edema, at 72-96 hpf. These results will assist in elucidating the mechanisms of the developmental toxicity of green synthesized Zinc oxide nanoparticles during the embryonic development of zebrafish.

Hummer’s method, in which potassium permanganate (KMnO4) acts as the oxidant and concentrated sulfuric acid (H2SO4) serves as the intercalator is commonly used to prepare Graphene Oxide (GO). The amount of the intercalator, oxidant, and graphite are important factors that affect the properties and structure of graphene oxide. In this work, a detailed investigation is carried out to optimize the mechanism of Hummer’s method in order to get the maximum yield of GO and reduced graphene oxide (rGO). XRD, SEM, TEM, FT-IR, TGA, Raman spectroscopy, and UV-Visible spectroscopy are used for characterization. XRD results of optimized samples (Opt-3-GO and Opt-3-rGO) clearly showed that the value of interlayer spacing is increased due to increasing the amount of oxidant and intercalator. SEM and TEM results revealed that the Opt-3-rGO was highly wrinkled nanosheets as compared to the Opt-3-GO. The FT-IR results showed that the double amount of oxidant and intercalator had an effect on the functional groups in the structure of Opt-3-GO and Opt-3-rGO. TGA results indicated that Opt-3-rGO has higher thermal stability as compared to Opt-3-GO due to the lower defect density. The ratio of intensities of D and G bands (ID/IG) increased for Opt-3-rGO as compared to Opt-3-GO. UV-Vis spectra of Opt-3-GO showed a maximum absorption peak at 237 nm attributable to π-π* transition of the atomic C-C bonds. The prepared samples have their use in different applications such as electrode materials for batteries, capacitors, and solar cells.

In this research, a systematic study was carried out to prepare microcapsules with cellulose acetate as a shell polymer and n-octadecane as a core material with a phase separation technique. This study aimed to investigate and clarify conditions for optimal morphology and behavior of these microcapsules for Phase Change Materials (PCMs). The optimal core-shell weight ratio, polymer molecular weight, and emulsification method were investigated. Using cellulose acetate with higher molecular weight (52,000 g/mol) and a core-to-shell weight ratio of 2:1, microcapsules with a high encapsulation efficiency of 86.7%, melting and crystallization enthalpies of 132.33 (J/g) and 91.24 (J/g) were obtained. It was also observed that the optimal method for preparation of the primary emulsion phase was via magnetic stirring in comparison with ultra-sonication (40.9%). The average particle size distribution of microcapsules was 20.48 μm, with an average shell thickness of 0.777 μm. The method used in this study was simple, fast, and low cost-effective. With an easy-to-scale-up feature, and not requiring high temperatures or phase change starters, these novel microencapsulated PCMs are ideal for industrial use.

In this research, a Glassy Carbon Electrode (GCE) was modified with glucose oxidase (GOx)/chitosan (CS)/Graphene Oxide (GO) nanofibers for the detection of glucose via the electrospinning method. To do this, GOx was trapped among the two CS/GO nanofibers layers. Concerning electrochemical properties and producing conditions, the optimum amounts for GOx and GO in the deposited layer were 20 mg/mL and 20 % w/w, respectively. An investigation on the effects of pH, time of oxygen dissolving in the test solution, and scan rate on electrochemical behavior revealed that the peak current increased with increasing the oxygen dissolving time up to 20 min and scan rate values. However, the redox processes showed more symmetric anodic and cathodic structures at slow scan rates. Also, the highest current was obtained at a pH of 7.4. The result showed that the electrochemical process of GOx occurs through a two-proton and two-electron transformation. Additionally, the sensor exhibited excellent reproducibility and stability properties. It was concluded that the use of nanofibrous structure and the immobilization of the glucose oxidase among the two CS/GO nanofibers layers enhanced the electrochemical properties significantly due to the penetration of water-soluble glucose molecules in the porous nanofiber layers, which helped efficiently catalyze the oxidation of glucose and facile direct electron transfer for GOx. The resultant modified electrodes exhibited a high sensitivity of 1006.86 μA/mMcm2 and a low detection limit of 0.02 mM with a wide linear range of 0.05–20 mM.

In this research, the ability of magnesium oxide (MgO) nanoparticles to the adsorbent was studied for the removal of Sunset Yellow (SY) dye in an aqueous solution. Different techniques, including Fourier Transform InfraRed (FT-IR) spectroscopy and Scanning Electron Microscopy (SEM) were employed to identify the adsorbed dye. Adsorption experiments were carried out in a batch mode with varying pHs, MgO concentrations, initial dye concentrations, contact times, and temperatures. To study SY adsorption's efficiency on the surface of MgO nanoparticles, pseudo-first-order, second-order, and intra-particle diffusion kinetic models were investigated. The pseudo-second-order kinetic model demonstrated a better fitting than other kinetic models (correlation coefficient: R2=0.99). The Freundlich model with an R2=0.93 value proved to fit with equilibrium data. In addition, thermodynamic parameters consisting of enthalpy, entropy, and activation energy were calculated too. It was noticed that the adsorption of SY on MgO was exothermic and spontaneous at low temperatures. The suggested adsorbent can be utilized for removing SY with an efficiency of more than 85%.

In this work, Zn2(BDC)2(DABCO) metal-organic framework (MOF) was prepared by Zn = zinc acetate dehydrates, BDC = 1,4-benzenedicarboxylate, and DABCO = 1,4-diazabicyclo [2.2.2] octane. The MOF and its polyurethane (PU) nanocomposite were used to remove Methylene Blue (MB) as a harmful and toxic dye from an aqueous solution. Polyurethane polymer has been modified with a zinc-based metal-organic framework by the press method to develop an efficient adsorbent for the first time. Samples were characterized by Fourier Transform InfraRed (FT-IR) spectroscopy to evaluate functional groups, X-Ray Diffraction (XRD) analysis of crystal structure, field emission scanning electron microscope (FESEM) to determine morphology and size, BET analysis for measurement of surface area, and Ultraviolet–Visible (UV–Vis) spectroscopy to study MB adsorption. Methylene blue adsorption was reported by changing the amount of adsorbent, MB concentration, pH, and temperature of the solution over time. According to the results, increasing the amount and percentage of adsorbent, pH, and temperature of the solution increased the percentage of adsorption efficiency. Also, the MOF and its nanocomposite can be a good choice for the adsorption of methylene blue as a cationic dye due to its high level and low material consumption. The results show that Zn2(BDC)2(DABCO) MOF and its PU nanocomposite can have good potential for the development of various adsorbents.

Biosorption of Cr(VI) ions onto Walnut Flowers (WF) is studied in a batch system in relation to the physical parameters. The efficiency approaches 100% with 5 g WF/L at pH~1.5  for a Cr(VI) concentration of 100 mg/L in less than 1 h. The experimental data are analyzed using two-parameter models (Langmuir, Freundlich, and Temkin), and three-parameter models (Redlich–Peterson, Sips, and Toth). In order to determine the best isotherm, two error analysis methods are used to evaluate the correlation coefficient and chi-square test. The error analysis demonstrates that the three-parameter models better describe the Cr(VI) biosorption data. The Sips equation provides the best fitting. The possible interaction between the Cr(VI) and the biosorbent surface was evaluated by FT-IR analyses. Overall, the proposed biosorbent material was successfully used for the removal of a Cr(VI) from contaminated solutions.

We conducted electro-oxidation, and combined electro-oxidation and electro-coagulation batch experiments on synthetic wastewater containing an anti-diabetic drug metformin hydrochloride (MET-HCl). Degradation and mineralization were studied on Ti/DSA (Ta2O5-Ir2O5) and stainless steel (SS) anodes. Electrochemical behavior was observed by cyclic voltammetry techniques. The effect of applied current density was evaluated at 50 ppm concentration of supporting electrolyte sodium sulphate (Na2SO4). Electro-oxidation on Ti/DSA anode resulted in maximum degradation of 94.88% at the corresponding specific charge (Q) of 2.1 Ah/L, current density of 0.93 mA/cm2 and Na2SO4 concentration of 100 ppm. Similarly, maximum mineralization obtained was 70.64% at corresponding specific charge (Q) of 2.1 Ah/L, current density of 0.93 mA/cm2 and Na2SO4 concentration of 50 ppm. Energy consumption was 2081.56 kWh/kgTOC. Further, under identical conditions, combined electro-oxidation and electro-coagulation on SS anode resulted in maximum degradation of 99.48% at corresponding specific charge (Q) of 2.1 Ah/L, current density of 0.93 mA/cm2 and Na2SO4 concentration of 100 ppm. Similarly, maximum mineralization obtained was 99.04% at corresponding specific charge (Q) of 2.1 Ah/L, current density of 0.93 mA/cm2, and Na2SO4 concentration 75 ppm. Energy consumption was 870.98 kWh/kgTOC.

An effective method for the preparation of stable dispersions of graphene is the direct exfoliation of graphene from graphite flakes in the aqueous solution of surfactants. Physical adsorption of surfactants on graphene surfaces is an important step in dispersing and stabilizing exfoliated graphene sheets in the aqueous medium. Dispersion of graphene with a mixture of surfactants is an effective way to obtain stable graphene sheets. The effect of synergism on a mixture of surfactants can reduce the total concentration of surfactants required for a particular application. The present study employed molecular dynamics simulation to investigate the adsorption of mixed cationic-rich and anionic-rich surfactants onto armchair graphene. We investigated the effects of temperature, electrolyte, and alcohol in the aqueous solution of surfactants on the adsorption process to understand the adsorption and self-assembly mechanism of surfactant mixtures on the graphene surface and also to better optimize the graphene dispersion process. The simulation results suggested the improved stability of these systems by adding an electrolyte to the aqueous solution of the surfactants. The screening effect of electrolyte ions on the electrostatic repulsion between groups of charged heads of surfactants has led to a denser accumulation of surfactants on graphene and more favorable interactions between them. Increasing temperature, however, reduced the system's stability by desorbing the mixed surfactants from the graphene surface. Comparing the surfactant molecules and graphene in terms of energy levels of Lennard-Jones interactions with and without alcohol also showed increased interactions in the absence of alcohol, which helps improve the system stability.

Alum is a widely used coagulant around the world, but its use of it is associated with some problems, as it increases the aluminum residuals, which have been linked to Alzheimer's disease. Coagulant aids may help with reducing the needed dose of alum. In this paper, many sets of experiments were done to determine the effect of using bentonite clay as a coagulation aid. The experiments were performed under different conditions and on different seasonal circumstances, where many alum and bentonite clay doses were used at low to medium initial turbidity levels. It was found that the addition of a small dose of bentonite clay; 5 mg/L improves the coagulation efficiency between 5 to 7.5 % for the Alum dose 10 mg/L and between 10.6 to 14% for the alum dose 15 mg/L. The coagulation process was also studied by changing both the temperature and the pH value; the best performance of bentonite was when pH is 5 and 6, and when the temperature changed between 10 to 25, the improvement of the removal percentage was about 30 % for the low turbidity and about 9% for the high ones. Finally, the effect of changing the settling time and the mixing speed were also studied. In this regard, it was observed that the best settling time was 90min and the best stirring speed was 200 rpm.

The widespread deposition of microplastics (<5.0 mm) in the marine environment has appeared to be pervasive across the globe. It has led to the major attention of many researchers to study this problem. Despite the amount of work conducted to understand these infamous microplastics, there is still no standard procedure for microplastics extraction from marine organism samples. This study investigated three types of digestion treatments; (1) KOH, (2) KOH/H2O2, and (3) KOH/NaClO, followed by density separation using 50% KI to extract the spiked microplastics from the rock oyster. Each treatment was tested to study the digestion effectiveness of the organic soft tissue materials while preserving the microplastic particles. Aside from recovering the spiked microplastics, other small contaminants have been detected in each treatment. All the spiked microplastics and the contaminants obtained were analyzed using a microscope and FT-IR for characterization. From this study, it was observed that each treatment resulted in high microplastics recovery. Among the three treatments, using 10% KOH alone provided the highest digestion rate, but it required more time to digest the oyster soft tissue. The contaminants detected in the oyster suggested the possibility of microplastics accumulation in non-digestion organs through adherence.

In the sweetening process, acidic and sour gases, including CO2, are separated and transferred to the sulfur recycling unit. CO2 is one of the impurities in natural gas. In addition to its harmful effects on the environment, pipelines, and refinery equipment, it also has many benefits in the field of oil, gas, and petrochemicals. For this reason, the ability to Separation rate CO2 emissions by high-efficiency tools that are also economically viable is important. In this study, modeling this process before operation can be an important step in reducing the high cost of separation. In this research, the CO2 separation process using membranes has been modeled by MATLAB software, Then, the effect of CO2 separation on sulfur recovery rate was performed using sulfur recovery unit simulation by Promax software. As a result, the highest amount of sulfur recovery in the membrane process in Poly Ether Urethane Urea membrane at the level of 100000 m2 with a selectivity of 1.65 in which the amount of S2, S3, S4, S5, S6, S7, and S8 are 0.1897, 0.0191, 0.01615, 4.668, 291.3737, 121.5916, and 1821.651 kmol/h, respectively. In poly ether urethane urea membrane with a selectivity of 1.65, the optimal point is obtained at a pressure of 35 kPa and a flow rate of 72.613 mol/s. The optimum point in the dimethyl silicon rubber membrane is achieved at a permeability pressure of 25 kPa and a flow rate of 98.4847 mol/s.

Tartrazine color is a synthetic organic food dye that can be found in common food products such as bakery products, dairy products, candies, and beverages, the presence and content of tartrazine color must be controlled in food products due to their potential harmfulness to human beings. Although the liquid chromatographic, and other methods for tartrazine color has advantages such as excellent accuracy and reproducibility, it has limitations such as long-time measurement, and high equipment costs. In this study, to determine tartrazine color in the solution we used a prepared from Mandarin Leaves-capped AuNPs sensor and kinetic spectrophotometric method. The calibration curve was linear in the range of (0.02 to 12.0 µg/L). The standard deviation of (3.0%), and detection limit of the method (0.02 µg/L in time 7 min, 385 nm) were obtained for sensor level response Mandarin Leaves-capped AuNPs with (95%) confidence evaluated. The observed outcomes confirmed the very low detection limit for measuring the tartrazine color in food samples. The artificial neural network model was used as a tool very low for determining mean square error (MSE = 0.515)  for tartrazine color by Mandarin Leaves-capped AuNPs sensor. The chemical Mandarin Leaves-capped AuNPs sensor made it possible as an excellent sensor with reproducibility.

In this study, a simple, fast, and inexpensive method is introduced to extract and determine remaining diphenylamine (DPA) in fruit samples by the combination of Dispersive Liquid-Liquid MicroExtraction (DLLME) and Ion Mobility Spectrometry (IMS). The main parameters such as the type and volume of extraction solvent, volume of dispersive solvent, salt addition, centrifugation time, and sample pH that affected the extraction efficiency were evaluated by performing single-factor variable experiments. Chlorobenzene was selected as the extraction solvent, which was dispersed into samples with methanol as the dispersive solvent. In the optimized experimental conditions, the suggested technique showed good linearity in the range of 25-550 µg/L with a correlation coefficient (R2) 0.997. The detection limits were obtained based on S/N of 3 as 7.5 µg/L in the standard solution and 17µg/kg in apple and pear samples. The repeatability and reproducibility of the method expressed as intraday (n=5) and interday (n=3) relative standard deviations were 6.0 and 7.5%, respectively at a concentration level of 150 µg/L DPA, and the enrichment factor was 36.0. Analysis of fruit samples for measurement of DPA showed that the introduced method has great potential to extract and determine the DPA in real samples.

QSAR investigations of Caspofungin derivatives were conducted using Multiple Linear Regression (MLR), Artificial Neural Network (ANN), and Monte Carlo Methods. The obtained results were compared and GA-ANN and ICA-MLR combinations showed the best performance according to its correlation coefficient (R2) and Root Mean Sum Square Errors (RMSE). The most important physicochemical and structural descriptors were presented and discussed. Monte Carlo method revealed that the presence of a double bond with branching, a six-member cycle, the absence of halogens, the presence of sp2 carbon connected to branching, the presence of Nitrogen and Oxygen atoms, absence of Sulphur and Phosphorus are the most important molecular features. The best Caspofungin derivative was exposed to reaction with Cu, Zn, Fe using B3lyp/6-311g/lanl2dz to investigate the stability of the formed complexes, from which the Zn complex was perceived to be the most stable one. It was concluded that QSAR study and the Monte Carlo method can lead to a more comprehensive understanding of the relation between physicochemical, structural, or theoretical molecular descriptors of drugs to their biological activities and Lipophilicity.

A cotton-based hydrogel nanocomposite was effectively arranged through free radical graft co-polymerization of a combination of Acrylic Acid (AA), acrylonitrile (AN), and sodium acrylate (NaA) onto the texture pursued by the addition of Ag nanoparticles. Ammonium persulfate (APS) and potassium persulfate (KPS) were utilized as initiators within sight of a crosslinker methylene bisacrylamide (MBA). These samples are characterized by Fourier Transform IinfraRed (FT-IR), and X-Ray Diffraction (XRD) to affirm the hydrogel nanocomposite structure. At first, the influencing factors onto graft polymerization were efficiently enhanced to accomplish a hydrogel with a swelling limit as high as expected under the circumstances. The came about nanocomposite shows overly hydrophilic and superhydrophobic properties. In this manner, the grafted texture, specifically from oil/water, blends separated water with high separation productivity. The impacts of channel type, level of covered hydrogel on cotton, nearness of Ag nanoparticles, extricated oil type, and temperature effect were studied on the hydrogel. Nanocomposite on the partition effectiveness of channels was additionally examined. The as-prepared materials were super hydrophilic and superoleophobic in air and submerged in water. Diesel oil and vegetable oil were used selectively at 10% and 20% volume in water. The separation efficiencies for each were observed on different samples, with and without Ag nanoparticles. The materials can isolate the scope of various oil/water blends (counting immiscible oil/water blends and surfactant-balanced out emulsions) with >97% separation efficiency. Effect of poly AN-CO-NaA and poly AN-co-AA ratios the samples show the same nature, their weight increases with time. The rates were different owing to the monomer ratios. Hence the more hydrophilic groups present, the greater the absorption rate, which shows the characteristics of this poly AN-co-AA grafted hydrogel. Sodium acrylate at different proportions in poly AN-co-NaA was tested, and it can be deduced that hydrophilicity increased with greater proportions of the sodium acrylate. Along these lines, the straightforward and effortless technique has superb potential in various applications such as industrial oil-polluted wastewater and oil spillage clean-up.

Cobalt and iron salt of mono manganese substituted Keggin polyoxometalate have been prepared and supported on silica as heterogeneous catalysts. The prepared compounds were completely characterized by conventional techniques such as FT-IR, ICP-OES, XRD, FESEM, and BET. The results indicated that the primary Keggin structure remain intact in the obtained samples and the prepared particles were in the nanoscale. The surface area of silica support decreased after loading of the cobalt or the iron salt of mono manganese substituted Keggin polyoxometalate on it. Application of the prepared compounds for demonstration of the effect of transition metals such as cobalt (or iron) combined with mono manganese substituted polyoxometalate was investigated in solvent-free oxidation of benzyl alcohol, as a test reaction, using H2O2. The results proved that the selectivity of the silica-supported cobalt salt of mono manganese substituted Keggin polyoxometalate catalyst to benzaldehyde was more than that of the other samples. The catalyst can be reused for several runs without losing significant activity.

The article presents the results of research on the synthesis of new medium alkaline AKI-31, AKI-57, and high alkaline additives AKI-124 and AKI-134. Additives AKI-31 and AKI-57 are calcium salts of condensation products of dodecylphenol, formaldehyde, and aminoacetic (AKI-31) or p-aminobenzoic (AKI-57) acid. Highly alkaline additives AKI-124 and AKI-134 are carbonated calcium salts of condensation products of dodecylphenol, formaldehyde, and aminoacetic acid (AKI-124) or p-aminobenzoic acid (AKI-134). The high-performance properties of the additives have been confirmed by standard research methods. Studies have shown that the additives have high antioxidant, anticorrosive, and detergent properties. Highly alkaline additives AKI-124 and AKI-134 were studied by thermal analysis methods. It is shown that the additives are highly resistant to temperature effects. By using highly alkaline additives, M-10G2 motor oils have been developed, which in terms of basic performance indicators correspond to GOST 8581-92 and are on a par with the foreign analog of Shell.

Aureobasidins (Abs) are a class of cyclodepsipeptides with interesting antifungal properties but they are difficult to synthesize. This study aimed to synthesize analogs of aureobasidin B (AbB) by a combination of solid- and solution-phase synthesis and to investigate their antifungal properties. The linear peptides were synthesized on 2-chlorotrityl chloride resin with Fmoc strategy and a range of coupling reagents including HATU/HOAt, HBTU/HOBt, and BTC/sym-collidine. The cyclization step was undertaken in the solution phase. Four cyclic nonapeptides (NP1-NP4) and ten cyclic heptapeptides (HP1-HP2, HP4-HP11) were successfully synthesized and characterized. The analogs NP1, NP4, HP1, and HP2 demonstrated moderate antifungal activity against Candida albicans

In this study, modified sulfonated polystyrene (SPS) was used as a base for membrane fabrication in Direct Methanol Fuel Cells (DMFCs). The sulfonated polystyrene (SPS) was prepared using ethylsulfate and polystyrene with sulfate attached to the para-position of some phenyl groups in polystyrene backbone and conducted by polyethylene (PE) and different amounts of MIL-53(Al)-NH2 as metal-organic material, to obtain SPS-PE-MIL-53 as a novel proton-exchange membrane. The membranes were characterized using FT-IR spectroscopy, SEM, and TGA analysis. The proton conductivity, water uptake, oxidative resistance, ionic conductivity, and methanol permeability of the membranes were examined to assess their performance in a direct methanol fuel cell. The modified membrane containing 1% wt SPS, 1% wt PE, and 0.25% wt MIL-53 showed relatively better performance than the other prepared membranes with the selectivity factor of 7.17 × 104 S.s/cm3 and a maximum peak power density of 17.04 mW/cm2 with a maximum current density of 115.38 mA/cm2.

Fish bones contain high calcium, which makes them a good raw material for the preparation of calcium hydroxyapatite (HAp). HAp is usually prepared from fresh fish bones because it has low impurity but there are many waste fish bones from food processing. In this work, HAp was synthesized from Budu waste by maceration process and calcination. Obtained products were characterized by X-ray diffraction (XRD), Fourier transform spectroscopy (FT-IR), and thermal analysis. When the calcination was higher than 600 °C, the product showed a mixture of hydroxyapatite [Ca5(PO4)3OH] as a major phase and merrillite [Ca9MgNa(PO4)7] as a minor phase. The amount of merrillite was increased with an increase in calcination temperature.

Natural products currently often consider starting points in drug discovery, followed by synthetic reforms to increase bioavailability and alleviate side effects. Approximately, fifty percent of the approved drugs by the U.S. Food and Drug Administration (FDA) are inspired by natural products. Glycyrrhizin is a well-known anti-inflammatory component that has been shown to prolong the coagulation time of thrombin and fibrinogen and to increase the duration of plasma recalcification. Suberosin, also known as 7-methoxy-6-prenylcoumarin, belongs to the class of coumarin compounds. The purpose of this article is to purify, identify, and standardize glycyrrhizin and suberosin, from Glycyrrhiza glabra L. and Ferulago trifida L. First, two plants were pulverized and then extracted using a percolator. The extracts were then divided into different fractions by column chromatography and mixed with thin-layer chromatography. Finally, we obtained pure compounds after using column chromatography and thin-layer chromatography. 1H-NMR and 13C-NMR have been used to purify compounds and also the HPLC method was used to standardize these compounds. Glycyrrhizin and Suberosin were extracted from Glycyrrhiza glabra L. and Ferulago trifida L respectively and 1H-NMR 13C-NMR techniques approved the structure of these two compounds, also, standardization of these compounds was correctly done by HPLC.

The unusual thermodynamic behavior of ionic liquid (IL)+CO2 mixtures has challenged their theoretical modeling. In this paper, a SAFT-γ equation-based group contribution method (SAFT-γ GC EoS) is used to predict the Vapor-Liquid Equilibrium (VLE) of these mixtures. The binary systems containing CO2 and 1-butyl-3-methyl-imidazolium-thiocyanate ([bmim][SCN]),1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]), 1-butyl-3-methylimidazolium dicyanamide ([bmim][DCA]), 1-hexyl-3-methylimidazolium dicyanamide ([hmim][DCA]), 1-ethyl-3-methylimidazolium tricyanomethanide ([emim][TCM]), 1-butyl-3-methylimidazolium tricyanomethanide ([bmim][TCM]) or 1-hexyl-3-methylimidazolium tetracyanoborate ([hmim][TCB]) are divided into the functional groups of CO2, cyano-based anion, CH2, CH3 and imidazolium-based cationic head. Some new SAFT-γ parameters are optimized at temperatures from 283.15 to 373.15 K and pressures up to about 20 MPa. The observation of an average error of 1.86% between experimental and estimated bubble pressures indicates the desirable performance of SAFT-γ GC EoS to predict the VLE of CO2+imidazolium-, cyano-based ionic liquid mixtures.

Phase diagrams for the ternary (neopentyl glycol + sodium formate + water) system were measured. Phase equilibrium data were obtained at different temperatures of 333.15, 343.15, and 353.15 K. The effect of temperature on the liquid–liquid phase equilibrium was studied and the length and slope of the tie-line at different temperatures for the conjugate phase were investigated. It was found that the tie-line length decreases and the two-phase area is slightly reduced by increasing temperature. The three fitting parameters of the Merchuk and Pirdashti equations were obtained with the temperature dependence expressed in the linear form, respectively. Compared with the Pirdashti equation, the binodal curves were described satisfactorily with the Merchuk equation, further, the plait points at various temperatures were estimated by extrapolation. The Othmer-Tobias and Hand models were used for the correlation of the phase equilibrium behavior. The correlation coefficients of the models were obtained for the corresponding temperatures. The results showed that it was well fitted with the Othmer-Tobias model by contrast with the Hand model.

Agitated vessels are frequently used equipment in industries, especially in polymer processes. In the present work, the CFD simulation technique was used to study the effect of impeller shapes in the industrial scale water-based polymers agitated vessels to increase mixing efficiency. The VOF multiphase approach and  turbulent model were used to study the hydrodynamic behavior of fluids in the vessel. The simulations were done in four designs, including designs A, B, C, and D. Designs A and B had three curved impellers with two  blades for each one and one straight impeller at the vessel bottom. Results showed that in designs A and B, the gas phase entered the liquid (polymer) phase and caused foaming liquid. In design C, a geometrical modification was done by removing the top curved impeller, adding a blade for curved impellers, and reducing of curved blade angle from  to . Results showed that wide rotational zones were achieved (about 75% of the liquid phase), and the liquid foaming problem was solved in design C. The modification of the bottom impeller in design D showed that the rotational zones cover about 95% of the entire liquid phase, which is the best performance compared to other designs. Also, the performance of design D was evaluated at the viscosity values, including 7,4,1 kg/m.s, and mixing quality was validated at these values.

Reactive distillation is carried out to produce methyl acetate from acetic acid and methanol using Indion180 as a solid ion-exchange resin catalyst in a simple distillation apparatus. Unlike the reboiler-column combination, a simple distillation apparatus is used to conduct reactive distillation where the vapors are condensed and collected as the catalytic reaction is proceeding in the reboiler flask. The aim is to quantitatively measure the distillate’s purity in terms of the methyl acetate’s mole fraction in it. The composition of instantaneous distillate, cumulative distillate, and of the reactant mixture in the reboiler is measured continuously.  The temperature in the reboiler as well as the electrical energy supplied to it is also measured as a function of time. A non-equilibrium evaporation rate-based model is proposed to predict the kinetics of the distillate and reboiler composition as well as the temperature. The reaction rate of the solid-catalyzed esterification process is modeled as per the pore diffusion model for the heterogeneous part as well as the homogeneous reaction. No previous studies are available with this concept of reaction kinetics in combination with the evaporation rate for reactive distillation. The experiment is conducted in simple distillation mode with nearly a constant heat input rate and developed a mathematical model for the obtained distillate composition. The overall model of reactive distillation is validated with the help of very few adjustable parameters found by minimizing the error between experimental data and model prediction.

The present work aimed to investigate the energy consumption and quality of tomato slices dried in an Infrared-Assisted Reflectance Windowtm (IRARW) dryer. The response surface methodology was used to optimize the experimental factors, including water temperature, infrared (IR) power, and belt speed based on specific energy consumption, IR fraction, contents of ascorbic acid, total phenolic, and total lycopene and color indices (L*, a*, b*, and H°). All factors, except the belt speed in the range of 0.278 - 0.37 mm/s, had significant effects on the performance parameters. The maximum measured value of specific energy consumption, IR fraction, contents of ascorbic acid, total phenolic, and total lycopene were 1.76 kWh/kg, 60.4%, 302.2 mg/100g, 708.07 mg GAE/100g, and 38.61 mg/100g, respectively. Rising IR power led to an increase in a* and a decrease in L* values of the color indices. The optimum drying condition was determined to be at the temperature of 70 °C and the IR power of 500 W.

Integrated Gasification Combined Cycle power plants generate electricity by utilizing the syngas obtained from the carbonaceous materials via gasification. These systems commonly use coal fuel; however, biomass fuels like bagasse could be a more environmentally friendly option. This study was aimed at analyzing the effects of varying operating parameters (such as temperature, pressure, O2/fuel, and water/fuel ratios), and fuel feedstocks (i.e., coal, bagasse, and coal-bagasse co-firing) on the syngas composition. Based on the data obtained from a commercial power plant, an equilibrium model was developed and validated using the Aspen Plus® software. Sensitivity analysis was carried out by varying the considered operating parameters and selected fuel feedstocks. The results of this study have manifested that low temperatures, low O2/fuel ratio, and high water/fuel ratio produce syngas with a comparatively higher H2/CO ratio. The highest H2/CO ratios of 1.16, 0.99, and 0.84, were obtained for bagasse, co-firing, and coal, respectively at operating parameters of 1200°C temperature, 0.5 O2/fuel, and 0.6 water/fuel ratios. Furthermore, bagasse and co-firing of coal-bagasse feedstocks could provide a better quality of syngas as compared to that of coal feedstock. The results of this study would also help to operate the Integrated Gasification Combined Cycle plants at optimum performance by utilizing different fuels and by appropriately adjusting the operating parameters.

The chemical analysis of dust particles is essential to assess the potential impacts of dust on climate, environment, soil, and health. The objective of this study is to compare the different chemical compositions of dust particles that are collected at different heights above the soil surface and the eroded soils around Lake Urmia. To trap the dust particles, the BSNE samplers were used. 14 poles were installed inside 3 ha. area and 4 samplers were installed on each pole at 0.15, 0.5, 1, and 2 m heights above the soil surface. Chemical properties such as %T.N.V, %OC, ECe, pH, and SAR of collected particles were determined. The results of variance analysis and mean comparison illustrated that there was no significant difference between the eroded soil and the particles sampled from 15 cm height among all the investigated chemical parameters. It proves that the source of the moving particles at > 0.15 m is different from the eroded soil. By elevating height above the soil surface increased, the %T.N.V, ECe, and pH decreased but the SAR and %OC increased. There was a strong negative and significant correlation between the monthly rainfall and the ECe, %T.N.V, and SAR, except for the %OC. The correlation between the speed of the strongest wind and the ECe, %OC, and SAR was positive and remarkable (P≤0.01). The pH was the only parameter that was independent of all meteorological parameters in this research. Furthermore, the SAR was the most sensitive factor to the meteorological parameters.

The amazing properties of structural gypsum make it a miracle material for finishing construction processes, especially from a health and environmental point of view. Chemically, the binding forces between gypsum molecules are limited to dipole-dipole interactions (hydrogen bonding) rather than that fixed conventional bonds. Such relatively weak bonds are responsible for the two common weak points including the water solubility and the relatively low hardness. Therefore, white Portland cement was suggested as an additive for treating those essential disadvantages of construction gypsum.  Samples of different ratios at 0.0%, 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, and 8.0% w/w of white cement to gypsum were made using 0.07x0.07x0.07m and 0.05x0.05x0.05m test cubes. The standard tests of physical and mechanical properties including hardness, compressive strength, setting time, and water resistance were measured. The results indicate that the presence of cement as an additive could eliminate the weak points of construction gypsum without any negative side effects. The study was supported by an aging investigation using thermodynamic and kinetic analyzes. In conclusion, it was strongly recommended to exploit white cement as an additive at a ratio of 4% w/w or 4.5% v/v for improving the physical properties of building gypsum. It was found that the presence of white cement at the optimum ratio of 4.0% w/w is not limited to eliminating the weak points of gypsum including the relatively low hardness and water solubility, but it extends to supporting other important properties including both compressive strength and setting time. The suggested additive has many desirable characteristics such as availability, healthy, economical, odorless, no coloring, used in few ratios, easy to deal with, and no volatile organic compounds (VOCs). The presented success can be applied by the construction industry for producing improved gypsum with no weak points.