Petroleum University of Technology
Recent publications
Water contamination due to the artificial dyes from domestic and industrial wastewater is one of the most crucial environmental issues and problems that the use of an effective adsorbent for dye adsorption seems necessary. In the present study, calcium alginate hydrogels reinforced with cellulose nanocrystals (CA/CNC) as a green and cost-effective adsorbent were utilized for the adsorption of methylene blue (MB). The characterization of CA/CNC hydrogel beads was performed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET). The MB adsorption kinetics data were consistent with pseudo-first-order model (R² > 0.99). The equilibrium data of MB adsorption was best fitted by the Langmuir isotherm model and showed monolayer adsorption on homogeneous sites. The maximum Langmuir adsorption capacity (qmax) as an index of the adsorption performance was obtained as 676.7 mg g⁻¹. The obtained results were analyzed by response surface methodology (RSM) and artificial neural network integrated with the whale optimization algorithm (ANN-WOA). ANN-WOA was coded using Python programming language. The contact time (min), shaking rate (rpm), and MB dye concentration (ppm) were considered as input factors for both methods. The fit of the predictive model by RSM was good enough with a correlation coefficient of 0.987. The ANN-WOA model with 3:7:1 topology resulted in higher correlation coefficient, lower root mean square error, and lower normalized standard deviation of 0.999, 0.758, and 15.320, respectively. However, evaluating the statistical criteria confirmed that ANN-WOA is superior to RSM for predicting the experimental data. Therefore, this work showed that CA/CNC hydrogels can be considered as a bio-adsorbent with a simple fabrication route and good adsorption capacity to remove MB from contaminated waters.
Nanomaterials have shown significant performances in enhancing oil recovery by reducing the interfacial tension (IFT) and contact angle (CA) of the rock/crude oil/water system in porous media. This is evaluated by the synergistic impact of silica–graphene quantum dots (Si–GQDs) on IFT reduction and wettability alteration for the purpose of enhancing oil recovery from carbonate reservoirs. The silica–graphene quantum dots (Si–GQDs) were synthesized by combining graphene oxide and silicon oxide nanoparticles (NPs) and characterized using several analytical techniques. Both distilled water and brine, as dispersion media, were used to prepare nanofluids by dispersing the synthesized Si–GQDs at different concentrations from 1000 to 10,000 ppm. The main properties of the nanofluids including pH, density, and conductivity were measured to evaluate their quality and the performance of Si–GQDs. In addition, the prepared nanofluids were used in the measurements of IFT and contact angles at different concentrations of the synthesized Si–GQDs in both types of used water. The obtained results show that the DWN1000 nanofluid formulated from dispersing 1000 ppm Si–GQDs in distilled water enables an additional 14.4% OOIP oil recovery due to a significant reduction in the value of IFT from 28.3 to 9.5 mN m–1, improving rheology behavior and wettability alteration toward a strong water-wet system from 134 to 61° contact angles.
Chemical vapor deposition (CVD) is a process that a solid is formed on a substrate by the chemical reaction in the vapor phase. Employing this technology, a wide range of materials, including ceramic nanocomposite coatings, dielectrics, and single crystalline silicon materials, can be coated on a variety of substrates. Among the factors influencing the design of a CVD system are the dimensions or geometry of the substrate, substrate temperature, chemical composition of the substrate, type of the deposition process, the temperature within the chamber, purity of the target material, and the economics of the production. Three major phenomena of surface reaction (kinetic), diffusion or mass transfer reaction, and desorption reaction are involved during the CVD process. Thermodynamically, CVD technology requires high temperatures and low pressures in most systems. Under such conditions, the Gibbs free energy of the chemical system quickly reaches its lowest value, resulting in the production of solids. The kinetic control of the CVD technology should always be used at low temperatures, and the diffusion control should be done at high temperatures. The coating in the CVD technology is deposited in the temperature range of 900–1400 °C. Overall, it is shown here that by controlling the temperature of the chamber and the purity of the precursors, together with the control of the flow rate of the precursors into the chamber, it is possible to partially control the deposition rate and the microstructure of the ceramic coatings during the CVD process.
Due to the desirable and interesting applications of refrigerants in organic Rankine cycles, heat pumps, and refrigeration, engineers and researchers are becoming more interested in refrigerant properties. One of the most dominant thermophysical properties of these fluids is their normal boiling point (Tb). In the current study, a novel extreme learning method (ELM) and ensemble decision tree boosted algorithm (EDT Boosted) are proposed to forecast the normal boiling point from 16 different molecular groups and one topological index. To this end, a total of 334 data points of Tb are gathered to prepare and test ELM and EDT boosted algorithms. The visual and mathematical comparisons of model outputs and real Tb express that proposed models have great potential to predict Tb of refrigerant. Moreover, sensitivity analysis is applied to explain the effectiveness of input parameters on the determination of Tb for refrigerants.
A computational method of data analysis based on an artificial neural network (ANN) has been proposed to model the behavior of a sol-gel coating modified with different amounts of oxidized multi-walled carbon nanotubes (O-MWCNT). The constructed ANN model utilized a single hidden-layer perceptron. The Lev-enberg-Marquardt algorithm optimization procedure was applied as a learning algorithm. In this model, the input variables were the different concentrations of O-MWCNT, the immersion time, and the real part of the impedance, and consequently, the imaginary part of the impedance was considered as the output variable. Then, the accuracy of the optimized model was evaluated using the correlation coefficient and schematically comparing the simulated data with the experimental ones in the Nyquist diagrams. Furthermore, the protection performance of the sol-gel layer was enhanced by the incorporation of O-MWCNTs. To this end, the different concentrations of the O-MWCNTs up to 0.9 % wt./wt. have been added to a silane layer, and the performance was followed by electrochemical exploration using electrochemical impedance spectroscopy (EIS). The results revealed the improvement of the protective performance of the silane coating by increasing the content of the O-MWCNTs in the matrix, followed by the enhancement of barrier properties. Moreover, the polarization curves, in agreement with the AC impedance spectra, reflected the significant decrease in the corrosion current density by employing more content of O-MWCNTs in the silane-based coatings.
In this research, optimization and statistical analysis of upgrading Iranian oil refinery residue in the presence of an H-ZSM-5 catalyst using RSM were performed. The residue (specific gravity: 0.9625, API: 15.5, viscosity (at 50 ⁰C): 275 cSt) was from Abadan oil refinery, Iran. Twenty-nine experiments were designed at five levels of temperature (360 to 440 ⁰C) and five levels of catalyst/feed ratio (30 to 70 wt%). The processing time in all experiments was 2 hr. The responses contained conversion, API, specific gravity, and viscosity. The catalyst was analyzed using XRD, SEM, EDX, and FTIR. RSM was used to model the responses. Quadratic polynomial equations were presented for the models. Based on the results, temperature and catalyst/feed ratio had significant effects on the responses of conversion, API, specific gravity, and viscosity. The interaction of independent variables was just significant for viscosity response. The carbon number variations for the feed and the product were 13 to 50 (230 to 582 °C) and 5 to 16 (47 to 273 °C), respectively. In the optimum conditions, including temperature: 439 °C and cat/feed ratio: 69 wt%, conversion, specific gravity, viscosity, and API of the upgraded residue were 64.09 wt%, 0.8202, 4.50 cSt, and 41.00, respectively.
This research aims to study the applicability of game theory to system safety and reliability decision-making problems and corresponding objective conflicts using non-cooperative games. The non-cooperative games would solve the games considering non-cooperative cognitive decision-makers behaviors, which are commonly ignored by other system safety and reliability analysis (SSRA) techniques , assuming that there would be perfect cooperation between the players (decision-makers). Game theory can also recognize and understand the decision-makers' behaviors and provide a "win-win" situation for all players and the best broader system outcomes. The paper also shows the use of dynamic game theory in system safety and reliability decision-making problems over time. The results indicate the effectiveness and efficiency of game theory and show how this can better reflect decision-makers' opinions in system safety and reliability decision-making problems.
Surfactant flooding is a promising CEOR approach in carbonate reservoirs and its efficiency has been verified. Commercial surfactants may impose various health and environmental issues. Therefore, utilizing a natural biodegradable surfactant at a low cost is a valuable option for the petroleum industry. In this research, a non-ionic surfactant derived from Acanthophyllum Plant Root Extract (APRE) was used as a bio-surfactant. The EOR potential of this surfactant was evaluated through various tests. Oil-water system interfacial tension (IFT) measurement, contact angle test for carbonate rock wettability alteration assessment, emulsion stability, compatibility, and surfactant flooding test were conducted. The effect of different ions of various salts on the IFT and carbonate rock wettability and the chemical interactions were also studied. The emulsion stability created by the surfactant was assessed through observational tests. The compatibility test (at 25°C) showed that negligible sediment below the salinity of 50000 ppm was formed. The IFT at CMC in formation water (optimum concentration of 12000 ppm) was reduced to 1.06 mN/m from an initial value of 2.16 mN/m. The optimum IFT value at different salinities was also determined. The wettability of the carbonate rock from a strongly oil-wet state (168°) was altered to water-wet (60.3°) in the presence of surfactant and FW with a concertation of 10000 ppm. In the core flood test, the effect of different slug sizes and soaking time was also determined. It was observed that increasing slug size results in a lower mobility ratio and consequently higher oil recovery.
The present work proposes an ultrasound (US) assisted electro-Fenton (EF) process for eliminating penicillin G (PNG) and ciprofloxacin (CIP) from aqueous solutions and the process was further optimized by response surface methodology (RSM)- Box-Behnken design (BBD). The impact of pH, hydrogen peroxide (H2O2) concentration, applied voltage, initial pollutant concentration, and operating time were studied. The capability application of the electro-Fenton (EF) and US processes was compared separately and in combination under the optimum conditions of pH of 4, a voltage of 15 V, the initial antibiotic concentration of 20.7 mg/L, H2O2 concentration of 0.8 mg/L, and the operating time of 75 min. The removal efficiency of PNG and CIP using the sono-electro-Fenton (SEF) process, as the results revealed, was approximately 96% and 98%, respectively. The experiments on two scavengers demonstrated that ⦁OH contributes significantly to the CIP and PNG degradation by SEF, whereas ⦁O⁻2 corresponds to only a negligible amount. The total organic carbon (TOC) and chemical oxygen demand (COD) analyses were used to assess the mineralization of CIP and PNG. The efficiency of COD and TOC removal was reached at 73.25% and 62.5% for CIP under optimized operating circumstances, and at 61.52% and 72% for PNG, respectively. These findings indicate that a sufficient rate of mineralization was obtained by SEF treatment for the mentioned pollutants. The reaction kinetics of CIP and PNG degradation by the SEF process were found to follow a pseudo-first-order kinetic model. In addition, the human health risk assessment of natural water containing CIP and PNG that was purified by US, EF, and SEF processes was done for the first time. According to the findings, the non-carcinogenic risk (HQ) caused by drinking purified water by all three systems was calculated in the acceptable range. Thus, SEF is a proper system to remove various antibiotics in potable water and reduces their human health risks.
UV-E-chlorination/hematite nanoparticles (UV/E-Cl/HNs) as a heterogeneous photocatalytic activation of electrogenerated chlorine was assessed for the degradation of bisphenol A (BPA) as a new approach based on the generation of reactive chlorine and oxygen species. The prepared sample was characterized using multiple techniques, such as XRD, FTIR, FESEM, EDS, and BET-BJH. An excellent decontamination efficiency of 99.4% was achieved within 40 min of electrolysis under optimum conditions (pH of 5, HNs dosage 100 mg/L, current density of 20 mA/cm2, and NaCl concentration of 50 mM). The HOCl content was reduced more swiftly in the presence of ultraviolet (UV) irradiation and hematite, resulting in the production of oxidative radicals (i.e., •OH, Cl•, and Cl2•- ). The scavenging experiments also verified the vital role of these radicals in oxidative treatment. The UV/E-Cl/HNs process is readily supplied with hydroxyl radicals through several mechanisms. Bicarbonate ions showed a noticeable inhibitory impact, whereas nitrate and sulfate anions only slightly affected BPA degradation. The HNs were a recoverable and stable catalyst for six cycles. Furthermore, the ECOSAR program predicted that the UV/E-Cl/HNs can be labeled as an environmental-friendly process. Eventually, reasonable degradation pathways were proposed based on the identified by-products through experimental and theoretical approaches.
In this study, the effect of pure Ni and Ni–SiO 2 nanocomposites coatings on corrosion, wear resistance and thermal conductivity of 316 stainless steel substrates was investigated with the purpose of extending the service life of 316 stainless steel plate heat exchangers. The nanocomposite coatings were developed by electroplating process in a Watts bath in different concentration values of SiO 2 nanoparticles (10, 20 and 30 g l ⁻¹ ). Electrochemical corrosion was run to examine the corrosive performance of the coatings. The results showed that the Ni–SiO 2 nanocomposite with concentration of 30 g l ⁻¹ had a higher corrosion resistance. A pin on disk wear test demonstrated that, in comparison to 316 stainless steel, the wear resistance of the Ni–SiO 2 nanocomposite (30 g l ⁻¹ ) was up to 25% lower while its friction coefficient was almost the same. In addition, as measured via the laser flash method and differential scanning calorimetry, the thermal diffusivity and specific heat capacity of the sample respectively were found to be 32 and 43% lower in comparison to 316 stainless steel. Microhardness measurement via a Vickers microindenter showed that the microhardness of the Ni–SiO 2 nanocomposite coating was more than three times higher than that of 316 stainless steel for all the reinforcement concentrations.
Amongst many chemical pollutants that cause environmental pollution, the presence of organic dyes in water resources can cause substantial health issues. Thus, owing to their mutagenicity and their adverse effects on human health, environment, and animals, they must be removed from industrial wastewater. In this study, UiO-66 metal–organic framework, as well as composite nanoparticles with carbonaceous materials such as MWCNTs-COOH and graphene oxide (GO) with different molar ratios (2.9 and 5.8 wt.%), were synthesized through solvothermal method since carbonaceous materials are an emerging material that demonstrates improvement in the properties of adsorbents. Then, the synthesized materials were utilized as a solid adsorbent for removing four different dyes including; anionic methyl red (MR), anionic methyl orange (MO), cationic methylene blue (MB), and cationic malachite green (MG) prepared from distilled water. The properties of prepared adsorbents were characterized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Photoluminescence spectroscopy (PL), Brunauer–Emmett–Teller (BET), as well as surface area analyzer and energy dispersive spectroscopy (EDS-MAP). Further, the influences of various factors including initial concentrations of the dyes and adsorption process time on adsorption of dyes were investigated. Adsorption experiments indicated that synthesized adsorbents exhibited the highest adsorption efficiency towards MR and MO dyes. Moreover, the experimental adsorption results revealed that MWCNTs-UiO-66 nanocomposites could adsorb 98% of MR and MO as well as 72% of MB and 46% of MG. Furthermore, the kinetic and stability of the materials over time were investigated. To reach a clear picture, adsorption experiments demonstrated that the amount of dye uptake on adsorbents was enhanced by increasing the contact time as well as uptake of materials with time were stable for both cationic and anionic dyes. The MR, MO, and MB adsorption isotherms were fitted with the Langmuir and Freundlich models. The Langmuir showed the highest agreement in these dyes and MWCNTs-UiO-66 (2.9 and 5.8 wt.%) exhibited a maximum adsorption capacity of 105.26 mg/g for MR, while the MG isotherm was in line with the Langmuir model.
The concentration point of this study is Criteria Weighting (CW) solutions which are the methods to determine the weights of the criteria in Multiple Attribute Decision Making (MADM). Although there are various CW methods in the related literature, there is no extensive typology framework or coding approach for the methods. Hence, this paper aims at establishment of a novel comprehensive typology scheme with consistent notations for the CW methods, conducting an extensive review of different CW methods, and identification of relevant classifications. The motivation is to help a fast access to the relevant literature, better capabilities to address suitable CW methods in real-world problems, and better communication among the MADM/CW researchers. The basic feature of the proposed approach is the identified underlying concepts (called rule) of the CW methods. Under the study, several rules were identified and coded. The paper also portrays a complete and up-to-date survey of the published literature on the original CW methods. In addition, to select appropriate methods in real-life situations, a set of brief guidelines are raised up. This helps decision/policy makers to choose the best-fit methods to employ in their real-life challenges.
In this study, the intensification of a UVC-based PMS activation treatment is performed by a novel photocatalyst. Using ZnO nanoparticles coupled with activated carbon (AC), impregnated by ferroferric oxides (FO, magnetite), as an effective Z-scheme photocatalyst (ZACFO), the effective Bisphenol A (BP-A) removal was attained. Several techniques were applied for the characterization of the as-prepared catalyst and proved the successful preparation of ZACFO. The photocatalytic activity of pristine ZnO was significantly improved after its combination with ACFO. It was found that the fabrication of ZACFO heterostructures could inhibit the charge carriers recombination and also accelerate the charge separation of photo-induced e− /h+ pairs. Under this UVC-based photocatalysis-mediated PMS activation system, ZACFO showed an excellent potential as compared to the single constituent catalysts. The complete degradation of 20 mg/L concentration of BP-A was attained in just 20 min with excellent reaction rate constant of 27.3 × 10− 2 min− 1. Besides, over 60% of TOC was eliminated by the integrated ZACFO/PMS/UV system within 60 min of reaction. The minor inhibition by most matrix components, the high recycling capability with minor metals’ leaching and the effectiveness in complex matrices, constitute this composite method an efficient and promising process for treating real wastewater samples. Finally, based on the photo-produced reactive intermediates and by-products identified, the Z-scheme photocatalytic mechanism and the plausible pathway of BP-A degradation were proposed comprehensively. The presence and role of radical and non-radical pathways in the decontamination process of BP-A over ZACFO/PMS/UV system was confirmed.
In this research, ZIF-7 particles were synthesized over graphene oxide (GO) nanosheets and characterized through various techniques. Then, the influence of the fabricated GO-ZIF-7 nano-hybrids on the weathering resistance and physical-mechanical performance of the PU coatings were investigated. The weathering resistance of PU/GO-ZIF-7, PU/GO, and control PU was examined with the aid of QUV accelerated weathering conditions via several methods such as recording gloss retention and contact angle changes, FTIR, colorimetric, FE-SEM, and AFM analysis. For the PU/GO-ZIF-7 nanocomposite coating exposed to accelerated weathering condition, the changes in carbonyl group relate peak and urethane linkage were less than the changes of these parameters for the control PU sample. The change in the color component (Δb*) decreased to 56.9% of PU/GO-ZIF-7 compared to control PU (70.9%). The change of root mean square (RMS) roughness value of PU/GO-ZIF-7 was less than that of control PU (from 9.44 to 8.04 nm vs. from 14.89 to 8.02 nm). As a result, after a long weathering exposure (UV-A), the fewer changes in aesthetic properties, chemical structure, and topology of the PU/GO-ZIF-7 coating led to less surface degradation and better weathering stability performance. The GO-ZIF-7 nano-hybrids revealed that they are capable of improving the photo-stability of PU coatings by the mixed mechanisms of absorbing UV rays and free radical scavengers. The physical-mechanical characteristics of the nanocomposites were analyzed using dynamic mechanical thermal analysis (DMTA) and tensile tests. The addition of GO-ZIF-7 to PU led to an above 70% and 85% increase of elongation at break and toughness concerning the control PU, respectively.
The use of nanoparticles (NPs) in enhanced oil recovery (EOR) processes is very effective in reducing the interfacial tension (IFT) and surface tension (ST) and altering the wettability of reservoir rocks. The main purpose of this study was to use the newly synthesized nanocomposites (KCl/SiO2/Xanthan NCs) in EOR applications. Several analytical techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM) were applied to confirm the validity of the synthesized NCs. From the synthesized NCs, nanofluids were prepared at different concentrations of 100–2000 ppm and characterized using electrical conductivity, IFT, and ST measurements. From the obtained results, it can be observed that 1000 ppm is the optimal concentration of the synthesized NCs that had the best performance in EOR applications. The nanofluid with 1000 ppm KCl/SiO2/Xanthan NCs enabled reducing the IFT and ST from 33 and 70 to 29 and 40 mN/m, respectively. However, the contact angle was highly decreased under the influence of the same nanofluid to 41° and the oil recovery improved by an extra 17.05% OOIP. To sum up, KCl/SiO2/Xanthan NCs proved highly effective in altering the wettability of rocks from oil-wet to water-wet and increasing the cumulative oil production.
It is shown that the depth of every module over C(X), the ring of all real valued continuous functions on a topological space X, is at most 1. This result is proved for modules over rings of a much more general class than the rings of continuous functions. It also turns out that many facts in the literature concerning the depths of C(X), their sub-algebras, and ideals are consequences of this main result. Some known results are generalized and some applications are given.
Hexadecyltrimethylammonium-bromide-activated zeolite nanoparticles coated with copper sulfide (ZEO/HDTMA-Br/CuS) was evaluated as a photocatalyst under sunlight for the degradation of metronidazole (MET). The surface and structural characteristics of ZEO/HDTMA-Br/CuS and other materials used in this study were analyzed using field emission-scanning electron microscopy, Fourier transform infrared and ultraviolet–visible diffuse reflectance spectroscopies, X-ray diffraction, Brunauer–Emmett–Teller surface area and Barrett–Joyner–Halenda pore size and volume analyses, and pH of zero charge test. ZEO/HDTMA-Br/CuS exhibited excellent surface and structural catalytic properties. For a comprehensive study of the degradation process, several parameters, such as the pH (3–11), MET concentration (10–30 mg/L), ZEO/HDTMA-Br/CuS dose (0.005–0.1 g/L), reaction time (5–200 min), and H2O2 concentration (50–200 mg/L), were optimized. ZEO/HDTMA-Br/CuS achieved 100% degradation efficiency when 10 mg/L MET was used under the optimum conditions: pH = 7, ZEO/HDTMA-Br/CuS dose = 0.01 g/L, and reaction time = 180 min. The degradation efficiency increased when the concentration of H2O2 was increased from 50 to 150 mg/L and decreased with further increase to 200 mg/L, indicating that the efficiency of MET degradation highly depends on the concentration of H2O2 in an aqueous solution. The degradation kinetics analysis revealed that the degradation is of the pseudo first-order. Thus, ZEO/HDTMA-Br/CuS proved to be an exceptional catalyst for the photodegradation of MET in aqueous media.
In this study, ferrate nanoparticles are prepared by solution plasma process and are employed for degradation of different dyes including Bromothymol blue, Cresol Red, Methylene blue, Methyl orange, Methyl Red, Methyl violet and Blue 203. TEM image indicates that particle size of synthesized nano-ferrate is lower than 50 nm. The effects of nanoparticle dosage, pH and temperature on dye degradation are examined. The degradation efficiency indicates that ferrate is capable for oxidation of dyes with high efficiency in very low reaction time. Moreover, removal efficiency of dyes increases more than 96 % by enhancing ferrate dosage especially with multiple addition of ferrate in very low dosage. The optimum temperature for oxidation is 25° and effective pH range is 6–8. The reaction kinetic of dye oxidation with ferrate is second order reaction and the calculated overall reaction rate constants indicate higher values for methyl orange and blue 203. The oxidation efficiency indicates no considerable variation in the presence of anions SO4²⁻, Cl⁻, and HCO3⁻ and monovalent cations K⁺ and Na⁺, while divalent and trivalent cations (Mg²⁺, Ca²⁺, Cu²⁺ and Fe³⁺) and humic acid inhibit dyes oxidation. In addition, real water systems including tap and river water without pH control are applied and the results show that removal efficiencies for most of dyes change very low. Mineralization efficiency of dyes measured by total organic carbon are about 50 % indicates that dyes are not degraded to CO2 completely. In addition, liquid chromatography equipped with mass spectrometry analysis after oxidation proves the TOC removal data.
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528 members
K. Salahshoor
  • Department of Automation and Instrumentation Engineering
Ahmad Shariati
  • Department of Gas Engineering
Mohammad Reza Khosravi-Nikou
  • Department of Chemical Engineering
Reza Mosayebi Behbahani
  • Departemnt of Gas Transportation and Process Engineering
Entrance of Ahvaz-Abadan Highway(39), Ahvaz, Iran
Head of institution
Dr. Karim Salahshoor