Iranian Journal of Chemistry and Chemical Engineering
Volume:41 Issue: 11, Nov 2022

The in-situ synthesis of KO2 nanocrystals on a porous fiberglass matrix is a promising route for the development of air regenerative products such as chemical lungs. The preparation process was studied experimentally with Taguchi experimental design L18 orthogonal array (35) to examine the effect of five physicochemical variables at three levels. Maximum active oxygen content (Oact wt.%) as the objective of optimization was determined by hot air at a temperature of 120 °C, flow rate 325 L/min, time of 10 min with 10 cm distance from the matrix, and alkaline solution 1.5%. The analysis of variance (ANOVA) with Fisher’s test revealed that the hot air temperature has the most significant effect on the response. The XRD pattern and TGA decomposition curves of the optimal sample confirmed the form of KO2 nanocrystals as a major phase on the matrix. The morphology and elemental analysis of the product determined by FESEM and EDX analysis have been evenly distributed both in pores and on the surface of the matrix in the form of spherical or quasispherical grains (10-40 nm in diameter). The BET-specific surface area of KO2 nanocomposite was measured about at 1.252 m2/g and they have a mesoporous solid structure. The best CO2 adsorption kinetic model was the Elovich model which fits the experimental kinetic data. The thermodynamic parameters represent the spontaneous and exothermic processes.

In this study, nanocomposites of Thermoplastic Polyurethane (TPU) clay are synthesized and used as a gas barrier property. The NCO-terminated TPU prepolymer was prepared by solution polymerization method using a 1:2 ratio of Polyethylene glycol (PEG2000) and Tolylene 2,4-diisocyanate (TPI). Organo-modified montmorillonite clay, Cloisite 25A(C25A) was used as ample compatibilization with PEG/TPI matrix. The prepared nanocomposite was characterized by Fourier Transform InfraRed (FT-IR) spectroscopy, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and ThermoGravimetric Analysis (TGA). The main functional group peaks of the nanocomposite materials are observed in FT-IR spectroscopy. The nanocomposites exhibited better thermal stabilities than pristine Polyurethane which is investigated by TGA. Thermal stability in the sample with 5 wt.% of TPU/C25A-5 material has improved up to 70ºC. The XRD results have confirmed the penetration of clay into TPU matrix, with the disappearance of the characteristic peak (2θ = 4.81º) corresponding to the d-spacing of the organoclay. SEM analysis confirmed the dispersion of nanoclay in TPU matrix. The mechanical properties of nanocomposites such as the tensile strength and Young's modulus of TPU/Cl25A nanocomposites were increased with increasing clay percentage. The gas permeability test was studied using a Membrane separation testing unit. Significant improvements in barrier properties were observed. A remarkable decrease was seen in polyurethane incorporated with 5 Wt.% organoclay when tested with oxygen and nitrogen gas.

In this study, Fe3O4/polystyrene-alginate nanocomposite with high adsorption capacity was successfully prepared. Characterization of Fe3O4/polystyrene-alginate nanocomposite was carried out by various instruments, including SEM, EDX, FT-IR, XRD, and TGA. Then, the prepared nanocomposite was applied to remove malachite green as a cationic dye from aqueous solutions. The kinetic study was performed and the results showed the suitability of the pseudo-second-order kinetic model (R2 = 0.994). The influence of different parameters, such as initial dye concentration, solution pH, adsorbent dosage, and contact time on the procedure was extensively investigated. The maximum adsorption of malachite green onto Fe3O4/polystyrene-alginate nanocomposite was found at an initial concentration of 20 mg/L, pH 7, adsorbent’s dosage 500 mg/L, contact time equal to 20 min. To understand the nature of the adsorption procedure, the equilibrium adsorption isotherms were investigated. The linear correlation coefficients of Langmuir and Freundlich isotherms were obtained. The adsorption of malachite green was better fitted to Langmuir isotherm (R2 = 0.996). According to the Langmuir isotherm model, the maximum adsorption capacity of Fe3O4/polystyrene-alginate nanocomposite for sequestering malachite green was about 90.81 mg/g. In addition, negative ΔG0 and ΔH0 values obtained through thermodynamic investigation implied that the adsorption of malachite green onto Fe3O4/polystyrene-alginate nanocomposite was simultaneous and exothermic in nature, respectively.

The creation of defiant chemical contaminants in the water is a major worry in water treatment processes. Such contaminants can never be readily eliminated with traditional treatment methods. As a result, combining adsorption with advanced oxidation processes is a critical method for removing harmful pollutants. This study aimed to investigate the efficacy of an environmentally friendly, low-cost catalyst that could be used as a heterogeneous Fenton oxidation catalyst. Ferric nanoparticles were synthesized from celery leaf extract (C-FeNPs). The Field Emission Scanning Electron Microscope (FESEM), Fourier-Transform InfraRed (FT-IR) spectroscopy, and X-Ray Diffraction (XRD) spectroscopy were used to describe the prepared catalyst. Adsorption isotherms of the chosen dye removal method were calculated and the tests were fitted with the Langmuir and Freundlich. The UV-vis spectrometer was used to determine the residual concentration of Orange Gelb (OG) dye in water. Under ideal parameters such as pH, temperature, and the concentration of OG and C-FeNPs dosage, the highest OG dye decolorization effectiveness of 99% was achieved. According to morphological analysis, nanoparticles with a diameter of 44–55 nm were shown to be responsible for the high catalytic activity. Adsorption data (R2 = 0.9436) is more consistent with the Langmuir model. Furthermore, the adsorption process was accompanied by an oxidation process more efficient.

In this study, eco-friendly composite material polyacrylamide/cellulose hydrogel reinforced with fuller’s earth (PAAm/CG/FE), has been synthesized and used for the effective adsorption of the Methylene Blue (MB) dye. The synthesis of PAA/CG/FE composite followed the free radical polymerization method. Chemical compositions and morphology of the synthesized composite have been characterized by Fourier Transform InfraRed (FT-IR) Spectroscopy and Scanning Electron Microscope (SEM). Thermal stability has been determined by TGA analysis. Batch adsorption experiments have been carried out by varying different parameters viz. contact time, pH of the solution, and temperature in order to determine the maximum dye adsorption capacity of the composite. Introducing cellulose and fuller earth into the polyacrylamide eventually enhanced the structural stability, thermal stability, and MB adsorption capacity. Based on the experimental data, adsorption kinetics has been found to be well correlated with the pseudo-second-order kinetic model. It has been found that the equilibrium adsorption isotherm data perfectly followed the Langmuir isotherm model and maximum adsorption capacities were found to be 48.30 and 56.17 mg/g for PAAm and PAAm/CG/FE composite, respectively. Furthermore, the prepared composite exhibits good reusability, and it is economic, eco-friendly, and nontoxic material.

The major goal of electric copper refinement is to manufacture high-purity cathode copper and minimize development expenditures. Elements (Bi, As, and Sb) have an adverse impact on the consistency of the ultimate cathode. Antimony is the key element in the moving sludge formation during the electrolysis phase. With increasing the electrolysis time, the antimony content in the electrolyte and the cathode-based antimony toxicity rise. In this research, CEC370 and Purolite S957 resins were used to isolate antimony (III) from the electrolyte. To evaluate the kinetics of the mechanism in static (discrete) conditions, pseudo-first and second-order, interparticle diffusion, and Elovich models were used. The results demonstrate that the pseudo-second-order model, with the greatest correlation coefficient (for CEC370 resin R2=0.991 and for Purolite S957 resin R2=0.997), can better estimate the kinetics of adsorption processes for both CEC370 and Purolite S957 resins. Furthermore, the results of the control phase of the ion exchange mechanism through the intraparticle diffusion models revealed that the phase of antimony (III) ions' arrival at the adsorbent film occurred at the highest rank. This may be triggered mostly by the agitation of the solution. The slope of the rating diagram (interparticle diffusion models) of CEC370 resin suggests is smaller adsorption rate compared to Purolite S957 resin. The saturation phase of Purolite S957 resin was achieved upon moving around 16 liters of electrolyte over the resin, and the saturation phase of CEC370 resin was achieved after moving about 10 liters of electrolyte over the resin in the ongoing process of antimony (III) elimination from the electrolyte (comprising 286 ppm antimony).

In this work, a method for preparing activated carbon based on cherry kernel shell (AC-CKS) was investigated using two consecutive steps: chemical activation with H2SO4 agent and thermal activation in air. For the first time, AC-CKS product is used for the removal of numerous metal ions such Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Zn(II), and Pb(II) from water solutions. The AC-CKS was characterized using EA, FTIR, SEM, EDX, and XRF techniques. The AC-CKS obtained by heating at 600 °C showed products with higher iodine numbers and invariably micro-size pores compared to those obtained by heating at 55°C and 400°C. The adsorption capacity of AC-CKS600 was tested in the removal of previously mentioned metal ions. The essential parameters affecting the removal of metal ions were studied. The results showed maximum adsorption of 99.0% for Cr(III), 91.7% for Fe(III), 62.0% for Cu(II), 59.3% for Pb(II), 42.0% for Zn(II), 28.0% for Ni(II), and 26.9% for Mn(II). The adsorption data of most metal ions fitted well with Langmuir model. The maximum adsorption capacity followed the sequence: Cr(10.75mg/g)>Fe(10.15mg/g)>Cu(7.58mg/g)>Pb(7.36mg/g)>Zn(6.08mg/g)>Ni(2.83g/g)>Mn(2.29 mg/g). The adsorption kinetics was tested for the pseudo-first order and pseudo-second order. The rate constants of adsorption for all studied metal ions were calculated. Good correlation coefficients (R2>0.9972) were obtained for the pseudo-second-order kinetic model showing that all metal ions uptake processes followed the pseudo-second-order rate expression. Desorption studies showed the quantitative recovery of metal ions in the range of 89.4% for Pb(II) to 94% for Cr(III). According to the adsorption model applied in this work, AC-CKS600 product could be recommended for the removal of Cr(III), Fe(III), Cu(II), Pb(II), and Zn(II) from aqueous solutions.

In this study, the removal of vitamin B2 from the aqueous solution using a synthesized multi-component nano-magnetic adsorbent modified by orange peel was studied. The structure and the morphology of the prepared nanocomposite were characterized using Fourier Transform InfraRed (FT-IR), X‐Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Brunauer–Emmett–Teller (BET), and Dynamic Light Scattering (DLS) techniques. The average size of the synthesized nanoparticles was 80 nm. The effect of experimental parameters such as pH, amount of adsorption, and contact time on vitamin B2 adsorption was investigated. Response Surface Methodology (RSM) based on the Central Composite Design (CCD) was used to obtain the optimum conditions for removing vitamin B2. Results revealed that the pH=5, adsorbent dosage of 0.4 g, and contact time of 180 min were obtained as optimum conditions. The isotherms (Langmuir, Freundlich, Temkin) and kinetic (pseudo-first-order, pseudo-second-order) studies were assessed. The data were fitted well with Langmuir (R2=0.9984) with qmax=53.47 mg/g and pseudo-second-order (R2=0.9984) models. The results showed that the two-component magnetic nanoparticle modified with orange peel, as an adsorbent, was suitable for the process of vitamin B2 adsorption from the aqueous solution.

In medicine and dentistry, the sterilization process is mandatory for the benefit of both patients and healthcare personnel. Tools used in treatment interventions should lack microorganisms and must be sterilized after every treatment intervention. Before sterilization, chemical cleaning solutions are used in washing machines in order to remove not only biological debris but also composite and adhesive materials remaining on stainless steel hand instruments. Before sterilization by use of an autoclave, additional mechanical cleaning is performed for still remaining debris according to the performance of the chemical procedure. Boron and boron products are found in the composition of many medical products such as lens solutions, creams, mouth rinse, and eye drops due to their antimicrobial properties. Graphene oxide is a water-dispersible graphene counterpart and with this fundamental property, it is often preferred in the formation of water-based hybrid materials. In this study, boron-doped graphene oxide sterilization pre-treatment solution was produced in order to clean hand instruments used in medicine and dentistry, and performance is compared with market products. Graphene Oxide (GO) was synthesized by the Modified Improved Hummers method without using sodium nitrate. Boron atoms were successfully doped into the GO structure with an atomic percentage of 2 (% w/w) by using boric acid (B) as a precursor. Surface structures and elemental analysis of the synthesized GO and Boron-doped GO (BGO) were made by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM).  BGO bond was observed by Fourier-Transform InfraRed (FT-IR) analysis. The efficiency of the BGO solution was tested and compared using cleaning process monitoring indicators.

The objective of this study is to characterize the Biosorbent (Atriplex Halimus leaves) and its application in the removal by adsorption of anionic and cationic dyes known for their toxicity such as Bemacid Blue (BB), Bemacid Red (BR), and Methylene Blue (MB) contained in water. The Atriplex Halimus was characterized by Boehm's method, FT-IR, XPS, SEM, pH Zero Charge Point (pHZPC), iodine value, and Methylene Blue value. The tests carried out in this experiment showed that the Biosorbent can remove Bemacid Blue (BB), Bemacid Red (BR), and Methylene Blue (MB). The effect of several parameters such as pH of the solution, biomass dose, contact time, initial concentration of dye used, and the temperature was studied in a batch system. The adsorbate-adsorbent equilibrium times are reached after 60 min for MB and 90 min for BB and BR. The adsorption is maximal for an adsorbent dose of 8 g/L for the three dyes. The best retentions were observed at pH 11, 6.45, and 5.12 for MB, BB, and BR respectively. The maximum adsorption capacities are 289.8, 29.7, and 32.9 mg/g for Methylene Blue (MB), Bemacid Blue (BB), and Bemacid Red (BR) respectively. Modeling of the experimental data showed that the Langmuir and pseudo-second-order models describe, respectively, the adsorption isotherms and the kinetics in a satisfactory way. The study of the thermodynamic aspects showed that the adsorption of the three dyes by the leaf biomass of Atriplex Halimus is a favorable, exothermic, and spontaneous phenomenon.

This study aims to determine the trace metals of (Mg, Fe, Cu, Pb, Cr, As, Ni, Zn, and Se) in some dried red plums specimens from Turkey. The metals in the dried red plum samples were determined using ICP-OES after solubilization in microwave digestion methods. With this technique, fast and high-precision determination of trace elements was made. Validation of the proposed method was carried out by using a NIST-SRM 1515-Apple Leaves certified reference material. Element concentrations in dried red plum samples were 44–47 (Mg), 15-18 (Fe), 03.1–3.2 (Cu), 4.1–4.4 (Pb), 1.4–1.6 (Cr), 1.1–1.3 (As), 2.5–2.8 (Ni), 3.4–3.7 (Zn) and 4.2–4.5 (Se) µg/g. The results were compared with the literature values.

Even though heavy metals are important plant nutrients when grown on contaminated soil or irrigated with polluted water, plants accumulate high levels of heavy metals and if consumed, negative health consequences occur. In this study, the accumulated potentially toxic metals in the edible part of selected vegetables, soil, and irrigation water along Dambo Dam of Jigawa state, Nigeria were assessed using the AAS method. Additionally, the translocation factor, the Monomial Ecological Risk (), and the potential ecological risk index of these potentially toxic metals on the selected vegetables were evaluated. The result revealed that the concentrations of these potentially toxic metals in water, soil, and vegetables are in the order Mn>Pb>Zn>Ni>Cd>Cu, except for lettuce where Pb was found to be higher than Mn. Furthermore, the concentrations of Zn, Mn, Cd, Pb, Cu, and Ni were all within the permissible limits set by World Health Organization. All the samples analyzed contained high levels of these metals, indicating evidence of contamination, which may be due to anthropogenic activity. The monomial ecological Risk (  of these metals in lettuce is in the order; Cd > Pb  > Ni > Zn  > Mn. While for cabbage, the order is Cd > Ni > Pb > Zn  > Mn. The Zn and Mn are within the Low-Risk values of  ˂ 40, and that of Cd is in the range of, considered very high, in both lettuce and cabbage. Whereas, Ni and Pb in cabbage are within  ˂80, considered a Moderate Risk. The highest Potential Ecological Risk Index (RI) was observed to be 400.24 in cabbage and 284.55 in lettuce, which is deemed very dangerous, as it is above the range of 200 ≤ RI ˂ 400.

Fluoridation is a process of adding fluoride to the treated water source as the fluoride present in the drinking water is beneficial in preventing dental and bone caries, especially for children.  The range for fluoride dosage concentration in drinking water systems is different from one country to another. In Malaysia, the allowable range of fluoride has been gazetted at around 0.4 to 0.6 mg/L. The source of fluoride from sodium silicofluoride (SSF) has been reportedly used due to its advantages compared to the other sources. In this work, the solubility of SSF as the fluoride source dosed at a dedicated Water Treatment Plant (WTP) was analyzed and different fluoride dosage range was evaluated from the WTP. This evaluation was done to ensure its single distribution system contains sufficient fluoride levels as recommended by the national drinking water standard. The solubility of SSF from different sources namely SSF1, SSF2, and SSF3 were studied at a different range of concentration using the gang jar test. Fluoride levels in the drinking water system were evaluated by taking the water sample from 7 sampling points, where fluoride dosages were grouped at three different ranges of fluoride concentration at the fluoridation dosing tank; (i) low (4.6 g/L), (ii) medium (7.1 g/L), (iii) high (11.8 g/L). Results show that at a high range of fluoride dosage, 10.4% of insoluble substance was recovered from the dilution of SSF3, which amount was found much lower than from SSF1 and SSF2. This finding indicates that SS3 is considered the best quality fluoridating agent compared to the other two sources to be applied in the fluoridation system. Spectroscopic analysis performed for the fluoride water samples shows that a high concentration of fluoride is required to obtain the concentration of fluoride at the allowable limit.  Meanwhile, the fluoride preparation at the dosing tank of medium range of fluoride concentration shows an average fluoride concentration level of 0.60 mg/L at all the seven (7) sampling points specified along the studied distribution system. Although the fluoride level is supposed to remain the same along the distribution system, the presence of various minerals and metals in the treated water may have caused fluoride concentration to reduce due to their reactions of them to form metal precipitates and/or complexes. Therefore, the dosage of SSF for fluoridation at WTP is recommended at the medium of-range fluoride concentration in order to obtain desired concentration at the distribution system within the allowable limit.

The acid gases (H2S and CO2) are unpleasant groups in the natural gas (sour gas) stream, which must be reduced. The presence of acid gases will have operational problems such as corrosion in the processing facilities and, environmental issues like air pollution and greenhouse effects. Therefore, the reduction of acid gases from sour gas is essential via a reliable process. The most common method for natural gas sweetening is the utilization of the amine solution. In the current work, the analytic hierarchy process (AHP) is employed to consider the advantages and disadvantages of each amine solution. The four process criteria and seven alternatives were intended based on the AHP procedure. Then, the natural gas sweetening process was simulated, and finally, operation conditions were optimized. MDEA as an alternative and cost as process criteria were introduced with 21% and 53% as the highest priority, respectively. The reduction of acid gas contents and reboiler duty were chosen as objective functions. The optimization results indicated that the best feed gas temperature and MDEA concentration are 30 ºC and 39 wt.%, respectively. The amount of H2S and CO2 as one of the optimization objectives of gas sweetening achieved 2.4 and 88 ppm in the optimal condition. Accordingly, the MDEA solution consumption was reduced by 5%, and reboiler duty decreased by approximately 0.04% compared to the conventional process.

The Zeolitic adsorbent is successfully synthesized by natural Iranian kaolin to the separation of hydrogen sulfide from a gas mixture. In this work, zeolite 13X from modified natural Iranian kaolin at 65 °C for 72 h at various concentrations of caustic soda solution was synthesized using a metakaolinization process at 900 °C for 2h. By Taguchi’s experimental design, the best duration and temperature of crystallization were 72 h and 65 °C. Prepared zeolite 13X was characterized using X-Ray Diffraction (XRD), Fourier Transforms InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), and N2 adsorption-desorption methods. In addition, the adsorption capacity of zeolite 13X for 310 ppm of hydrogen sulfide mixed with hydrocarbon gas-like butane was investigated using a volumetric method by two different detectors and different temperatures. After the adsorption process, the amount of H2S in output gas was about 108 ppm and this confirms approximately more than 65% adsorption at 25 bar and 298K. The results are is in good agreement with experimental results.

In the flotation of sulfide minerals, particularly in the separation between pyrite and chalcopyrite, adjustment of the pH and reagents dosages is very important.  Process auditing at the Sarcheshmeh copper complex showed that the pH in the rougher cells was greater than 12, while according to the initial design, the pH in the rougher cells should be 11.5.  Also, it was found that the collectors and frothers dosages were 21.6 and 25.1 g/t, respectively, which is much lower than the initial design.  Also, plant audit showed that this operation method was used because of an idea about higher froth stability and easier operation in the higher pH values.  In addition, it was observed that by suddenly changing the reagents and pH regime to the initial design, operation stability and therefore the copper recovery were also reduced quickly.  Hence, in this study pH was decreased and reagent dosages were increased step by step.  The results showed that after adjustment of the pH in the range of 11.5-11.7 and increasing the collectors and frothers dosages to 29 and 31 g/t, respectively, the copper recovery was increased by about 2%, and the operation stability was not reduced.

One of the most appealing compounds in biomass products is levulinic acid (LA). At the same time, separating LA from biomass products is a significant issue in LA production. Supported liquid membrane (SLM) is a revolutionary technique for separating LA from biomass. This study studied the effect of different casting thicknesses of hybrid polyethersulfone graphene membrane from 300 µm to 450 µm on the membrane characteristic and extraction yield of LA via the SLM process. The liquid membrane impregnated into the membrane support was made of 0.3 M trioctylamine and 2-ethyl-1-hexanol. The morphology, surface contact angles, porosity, tensile strength, and performance of the support membrane were evaluated. The membrane cast at 400 µm extracted the most LA (86%) from the 10 g/L LA feed phase. It had an average porosity of 57.77%, surface contact angle at the top layer of 81.21°, surface contact angle at the bottom layer of 98.02°, and tensile strength of 8.41 N. The membrane casting thickness impacts the character of the membrane support and the overall performance of SLM. A suitable membrane structure is required to overcome the instability of the liquid membrane and increase the lifetime operation of SLM.

The frankincense essential oil was successfully incorporated into nano-sized microemulsions systems through low energy self-emulsification technique. The effects of main formulation parameters, namely, surfactant, co-surfactant, essential oil, and water concentrations, as well as the mixing rate and temperature on mean particle size, polydispersity (PDI), turbidity and antioxidant activities of colloidal frankincense essential oil nanoparticles, were investigated. The results show that all studied independent parameters affect the most characteristics of frankincense essential oil microemulsions, significantly. The antibacterial activities of essential oils were also considerably increased as incorporated into nano-sized microemulsions. It resulted that the most desired frankincense essential oil microemulsions, with desired characteristics (less particle size, size distribution, turbidity, and greater antioxidant activity) could be obtained using high concentrations of surfactant (0.7 g), medium concentrations of co-surfactant, essential oil and water (0.2 g, 0.1 g, and 9.2 mL, respectively), and medium levels of mixing rate and temperature (500 rpm and 40 °C). Thus, by tuning the formulation or process parameters the most desired nano-sized essential oils can be prepared as natural preservers or health-promoting agents for various food and beverage applications.

Current research refers to the modeling of data from the extraction of essential oils from plant materials via the hydro-distillation method, which is applicable from the laboratory scale to the production scale. Experimental data from the process were obtained by studying the kinetics of the distillation of calamondin peel essential oil. Kinetic models are based on the extraction mechanism of the essential oil, which involves the amount of essential oil released from the plant cell. On the principle of extracting essential oils, the mechanism of washing and diffusing is the basis for constructing the kinetic model and its assumption is developed in order to give an appropriate model. The descriptive kinetics of the hydro-distillation process is based on two assumptions: instantaneous washing followed by non-stationary diffusion and first-order kinetics (diffusion without washing). These two models were compared to select the optimal model for the extraction process. The results showed that the calamondin peel essential oil extraction process was described by a non-stationary model with an extraction rate constant (k) of 0.038 min-1. The extraction of hydro-distillation essential oil from calamondin peels obtained the highest essential oil content (4.2%) under extraction conditions such as a water-material ratio of 3:1 mL/g, a heating power of 204 W, and an extraction time 60 min. Furthermore, the chemical composition of volatiles present in calamondin peels oil was evaluated for the sample by using GC-MS. Limonene (88.637%), Germacrene D (4.451%), β-Edudesmol (1.034%) were the major constituents in the essential oils.

In recent years, numerous studies have been done on the beneficial use of food waste. Pomegranate is widely used in food industries, and the skin of this fruit containing the valuable substance, pectin, is discarded as waste. The general aim of this study was to investigate the effect of temperature (35, 65, and 95 ºC), time (40, 120, and 200 min), and pH (1, 2, 3) on the galacturonic acid percentage, Degree of Esterification (DE), and yield rate of pectin extracted from pomegranate peels and optimize extraction conditions. Therefore, 15 treatments were designed using the response surface methodology Box-Behnken and the obtained results were analyzed and optimized by using the response surface method at a confidence level of 95% in Minitab 16 software. The results of the analysis of variance (ANOVA) showed that the linear effect of temperature, time and pH had significantly (p ≤0.05) affected the amount of pectin extracted from pomegranate peels. Results showed that hard extraction conditions (lower pH, higher temperature, and greater time) have increased the extraction yield and the amount of galacturonic acid of pectin, while these conditions have reduced the degree of esterification of pectin. According to the results, the yield of pectin extracted from pomegranate peels, the percentage of galacturonic acid, and the degree of esterification varied from 6.96% to 8.65%, 60.31% to 84.64%, and 52.30% to 65.21%, respectively. The multiple optimum extraction conditions to achieve maximum yield of pectin extraction (8.65%) and galacturonic acid (83.49%) with 97.60% desirability were obtained at 94.39 °C, time= 200 min, and pH = 1.24. The results of this study proved that pectin can be extracted from Saveh pomegranate peel with desirable quality properties and used in food formulations

The white soil is used as a clarifier, in the traditional preparation process of grape syrup, to reduce the acidity and deposit the suspended colloidal substances. Besides increasing the nutrients in grape syrup, the substances in white soil may also have side effects on the final product. In grape syrup production, heating the grape juice and soil mixture to the boiling point makes more soil absorption. Determining the chemical composition and the concentration of the used white soil is vital for producing a healthy product. In this study, white soil samples were collected from 10 areas commonly known as white soil excavation sources in Malayer city, Hamadan, Iran. The dry white soil samples were then prepared to be analyzed by the Proton Induced X-ray Emission (PIXE) technique. Ca had the highest and Mg had the lowest value of concentration among the detected elements of Mg, Al, Si, S, K, Ca, Ti, Mn, and Fe in the collected samples. From the statistical analysis, it was revealed that the Ca content of the soil is significantly incompletely correlated with other detected elements. In addition, Ca, Si, and Al had a significant difference (p < 0.001) with other identified elements. The higher amount of Mn and Fe makes the darker color of the syrup while the higher content of Ca increases the transparency of the syrup color. The grape syrup made from the soil containing the highest level of Ca was tasty, more transparent, and light brown in color.

In this work, the study of the rheological behavior of the aqueous solution of cationic surfactant, cetyltrimethylammonium bromide (CTAB) and nonionic polymer, polyethylene glycol (PEG 3000) has been carried out. Response surface methodology of design of experiment technique was adopted to identify the effect of different variables and their interactions on viscosity. A preliminary experimental investigation was carried out to evaluate the rheological behavior of aqueous PEG, aqueous CTAB, and also of the binary solution of them. It is found that they all show Newtonian behavior for a shear rate of up to 1000 s-1 for the studied concentrations. For the shear rate above 1000 s-1 aqueous PEG solution shows shear thickening behavior. Combinations of levels of variables i.e. [surfactant], [polymer], and temperature were determined using a face-centered central composite design (FCD) of response surface methodology. Through regression, a quadratic model was generated and found to be very accurate in describing the relation between response and parameters with R2 =0.987, predicted R2 =0.9412and adjusted R2 =0.9776. The effect of interaction between surfactant and polymer on dynamic viscosity is identified with the help of contour and response surface plots. A sudden increase in viscosity is observed at low CTAB concentrations which were the result of weak interactions between CTAB and PEG and the effect of these interactions is found to be more pronounced at high temperatures.

The effect of stirring on the amyloid fibrillogenesis of β-Lactoglobulin (βLG) at pH 7 was studied in the presence of glucose (Glu). Fibrillogenesis was carried out by heating the 0.30 mM βLG solution at pH 7 with and without glucose (37.5 mM) for 24 hrs at ≥80◦C under stirring (250 and 474 rpm) conditions. For control samples, βLG solutions with and without glucose were incubated under unstirred conditions. The flow-induced birefringence method was used to characterize the fibrillogenesis, revealing the coil-stretch transition and pointing out the existence of worm-like flexible fibrils in all samples. Atomic Force Microscopy (AFM) was used as a morphology that clearly showed the flexible fibrils in all samples and also revealed that the fibril lengths shortened on increasing the stirring rate. This shortening in lengths might be possible due to weak hydrophobic interaction at pH 7 resulting in fragmentation of fibrils over stirring. Glucose inhibited the fibrillogenesis of βLG even on stirring.

This paper aims to investigate the robust control problem of Continuously Stirred Tank Reactors (CSTR). A CSTR is one of the most essential pieces of equipment in chemical processes, whose effects of highly nonlinear dynamic and external disturbances make it very difficult to be controlled. Firstly, a novel finite-time sliding mode control is introduced that eliminates disturbance effects and ensures finite-time tracking. Secondly, to better compensate for disturbances and to improve controller performance, a finite-time disturbance observer is developed. Finally, an adaptive robust control method is introduced based on the proposed sliding mode control and the disturbance observer. Stability analysis is performed to investigate the finite-time tracking of the closed-loop system under the proposed controllers. Besides, to enhance the performance of the proposed controllers, the design parameters are tuned by the genetic optimization algorithm. Simulation results are produced to confirm the efficiency of the proposed methods in terms of tracking errors and convergence rates. The proposed finite-time sliding mode control and the adaptive finite-time sliding mode control with settling times of 1.73s and 1.71s as well as IAE of 0.509 and 0.4843, respectively, showed more desirable performance than other controllers.

Pore space characterization helps a better understanding of porous media. The pore geometry and topological properties in carbonated rocks are important for a better understanding of the complex hydrologic and elastic properties. A detailed model of the pore space constructed directly from three-dimensional images can bring reliable results because the porous media complexity would be considered. In this study, by considering different methods a deep understanding of some carbonated pore spaces is obtained. Four series of 2D micro-computed tomography binary images for carbonated rock have been collected, and each of them was considered as a 3D binary image. Using novel skeletonization and pore-throat segmentation algorithms, some network properties have been evaluated and compared for the four cases. Those considered properties were pore and grain size distribution, throat length frequency, and coordination number frequency. Moreover, the geometric measures in 2D and 3D have been considered using Minkowski functionals. The area, the perimeter, and the 2D Euler number of 2D binary images and the volume, the surface area, and the mean breadth which is also known as the integral of the mean curvature and the 3D Euler Number of the 3D binary images are also considered.

The production of fuel from Waste Transformer Oil (WTO) is an excellent way to produce alternative fuels. The aim of research in this paper is to obtain fuel by mixing WTO with diesel fuel in different mass ratios that can be used as an alternative fuel for low-power heat generators as well as for internal combustion engines. Waste oils are a serious problem for the environment due to their disposal, and are considered useful energy sources for their high calorific value. Taking these facts into account, research was conducted to evaluate the combustion and emission parameters in a boiler furnace of 40 kW using waste transformer oil (WTO) and its four diesel blends by varying WTO mass fractions from 20% to 50%. The results were analyzed and compared with diesel fuel. An increase of NO, CO, CO2 emissions were observed for WTO and its diesel blends and compared to diesel. The flue gas temperature in the kiln is high for the WTO, which indicates the efficiency of the input energy. During the flue gas purification in a gas washing bottle, concentrates of sulfate, sulfide, nitrate, and nitrite were recorded.

Polymer solar cells are potential candidates for providing energy as an alternative energy source. In this type of solar cell, the active layer of the semiconductor material absorbs light. The P3HT: PPV layer was used as the active layer in this study. This research aimed to determine the impact of annealing and P3HT composition on the performance of solar cells. The annealing temperatures tested in this study were 120 °C, 135 °C, 150 °C, 165 °C, and 180 °C. Based on the findings, the annealing treatment affects the morphological structure of the active layer and the self-ordering crystallinity of P3HT, which PPV hampers. The results of SEM characterization revealed the effect of annealing on the morphological structure of the active layer. An annealing temperature of 150 °C produced the most homogeneous layers. The P3HT: PPV ratio was tested at 1: 1, 2: 1, and 3: 1. The 3:1 ratio yielded the highest efficiency, which was 3.5 percent. In this condition, an electric current of 0.04 mA and a voltage of 4.098 V were also obtained.

Alternative energy and renewable sources received considerable attention  from many researchers because fossil fuel has intermediate products during the conversion of coal. Intermediate products such as synthesis gas, biochar, and condensable vapors are directly influenced by the production of energy to mitigate the barrier to future energy demand. The present review deals with the pyrolysis of coal and the results of pyrolysis of coal investigated by the parameters affecting product distribution such as type of reactor, feedstock composition, temperature, heating rate, particle size, and sweeping gas flow rate. Intermediate products such as charcoal obtained at 300 to 400°C usually the product of a slow pyrolysis process because coal has a large content of un-burnt inorganic compounds in the form of NOX, SOX, and ash, bio-oil depend on volatile matters and obtained at temperature range 410 to 460°C as a product of fast and flash pyrolysis process because of high heating rate but during slow pyrolysis limited fraction obtained, gas formation observed when secondary cracking of coal at a temperature relatively higher to 500°C.  Environmental effects and part of the potential scope of coal pyrolysis-based studies are also discussed in this review. Therefore, in the future utilization of coal will be interesting to optimize the products.

IBiodegradability and antimicrobial activity of food packaging materials are the most important parameters of modern food packaging industries. Therefore, the present study aimed to use a biodegradable film of polyvinyl alcohol and pinto bean starch-containing cinnamon, garlic, and ginger essential oils to increase the shelf life and reduce the microbial load of the jug cheese and compare with conventional packaging. For this purpose, jug cheese in the biodegradability film of polyvinyl alcohol/pinto bean starch (20/80%) respectively and dissolved in distilled water for 60 minutes at 90 °C was heated at 400 rpm stir. T10% glycerol was added to the filtered solutions on a magnetic stirrer (400 rpm) for 30 minutes at 37 °C to obtain a completely homogeneous solution. To make an antimicrobial biocomposite, three concentrations of each of the essential oils containing different concentrations (3.125, 6.25, and 12.5%) of cinnamon, garlic, and ginger The prepared films were poured into Teflon containers with a diameter of 15 cm and exposed to ambient temperature for 24 hours. The dried film layers were removed from the Teflon surface and stored in a zip kept at 25 °C until their microbial and sensory properties were evaluated during 60 days of storage at 4 ° C and compared with the control sample.  The results showed that the use of biodegradable film containing essential oil significantly reduced the microbial load in jug cheese samples. Total count of microorganisms, amount of Staphylococcus aureus, coliform, mold, and yeast in samples of jug cheese packed in a biodegradable film containing 6.25 and 12.5% cinnamon essential oil and 12.5% ginger essential oil after 60 days of storage was within the acceptable national standard. The highest general acceptance score among the acceptable samples of national standard belonged to the sample of jug cheese packed in a biodegradable film containing 6.25% of cinnamon essential oil. The use of biodegradable films based on pinto bean starch and polyvinyl alcohol along with cinnamon and ginger essential oils are solutions that can reduce the microbial load and increase the safety of food products during storage and prevent environmental damage.

The dissolution of oxygen into the fermentation medium and the appropriate mass transfer conditions are of crucial importance in designing large-scale aerobic bioreactors. The investigation of mass transfer rates and flow structures in a large-scale process by only using experimental methods is hardly feasible, more likely because of the huge running costs. Also, those investigations by only using simulation approaches would not be accurate. Thus, this study is devoted to the application of a facile hybrid simulation/scale-down/experimental approach to optimize the structure and operation of a 400-L bioreactor used for the diphtheria bacteria culture. Assisted by the Computational Fluid Dynamics (CFD) simulation, the effects of engineering parameters such as the type, agitation rate, and location of the impeller, viscosity as well as the airflow rate and inlet place on the hydrodynamics of large-scale bioreactor were studied. Using the concaved blade disc (CBDT) impeller located at the 30-cm distance with an agitation rate of 550 rpm as well as the air inlet placed at the bottom with a flow rate of 20 L/min, a superior improvement in air distribution, bubbles size, and kLa value (0.64 s-1) was observed. To verify the simulation results, 15-L bench-scale bioreactors were developed by using a scaled-down (equivalent volumetric power (P/V)) strategy. The CFD simulation results implied that the bench-scale and large-scale bioreactors have comparable hydrodynamic environments. Additionally, the kLa values obtained experimentally were very close to the ones got by the simulation. These results make the CFD-assisted optimized 400-L bioreactor a potential candidate for this bioprocess.