Response surface methodology (RSM)

This study employs mathematical modeling and Computational Fluid Dynamics (CFD) to investigate the impact of contact angle, flow rate, and surface tension on slug and detachment length in a T-junction microchannel. The simulation focuses on creating a microdroplet at the center of the microchannel, surrounded by the continuous phase, exploring various flow patterns. Response Surface Methodology (RSM) is utilized to model two responses: the detachment length of slugs and the slug length. Three independent factors—Weber number in the dispersed phase (Wed), capillary number in the continuous phase (Cac), and contact angle (θ)—are considered at different levels based on CFD calculations. The Central Composite Design (CCD) is employed for experimental design, and 186 simulations are conducted to predict slug and detachment length. Furthermore, two quadratic correlations, Equations (12) and (13), with R2 values of 0.9780 and 0.9273, were developed, representing slug length and detachment length, respectively. These correlations are crucial for optimizing microfluidic device design and operation and by accurately predicting outcomes under different conditions, these equations help fine-tune systems for better efficiency and reliability. In conclusion, our study bridges gaps in understanding slug behavior within microchannels and offers insights into optimizing microfluidic systems through mathematical modeling and CFD simulations.

In the present study, NiO-MgO nanocomposite was synthesized by the Sol-gel process. Activated carbon was incorporated with the nanocomposite to yield activated carbon coupled Bimetallic Nanocomposites NiO-MgO-AC. The nanocomposite was utilized in an ultrasonic adsorption process to remove Methylene Blue (MB) dye from the simulated Dye effluent. FT-IR, EDS, and SEM were used to determine the chemical composition and structural morphology. The surface neutrality was calculated using PHPZ C, which was found to be 5.5. The experiments were carried out using a four-factorial central composite design with variables such as sonication time, MB dye concentration, pH, and adsorbent dose. To find Optimal Operating Parameters (OOP), the Response Surface Methodology (RSM) was employed. At a pH of 5.0, sonication time of 6.23 minutes, 0.02 g of the nanocomposite, and 10 mg/L concentration of MB dye. The removal efficacy was found to be 93.983%. Various isotherm models, including Freundlich, Langmuir, Temkin, and Dubinin Radushkevichat 303-313K temperatures, were used to study the adsorption equilibrium. The RL values were less than one, suggesting that the adsorption technique was suitable. Furthermore, the values of n were found to be larger than one, indicating that the Freundlich adsorption model was appropriate. The D-R isotherm provides values of E that were seen to be below 8.0kJ/mole at all temperatures indicating a physisorption process.  The thermodynamics of dye removal were also studied in order to obtain the system's DHo, DSo, and DGo values. The pseudo-first and pseudo-second-order, intraparticle diffusion, Elovich, and Boyd kinetic models were used to determine the kinetics of adsorption. The current study's findings indicated that nanocomposites can be efficiently utilized in waste treatment operations. The simulated dye wastewater treatment system was designed locally and can be efficiently employed on a commercial scale for the treatment of effluent before discharge into main streams to minimize its toxicity to the ecosystem.

A novel metal–organic framework (MOF), with the formula [Cu(II)L]n (L= 4, 4′-diamino diphenyl sulfone), has been synthesized conventionally and hydrothermally methods and characterized by FT-IR, PXRD, EDX, and SEM techniques. The results MOFs were applied for photodegradation of Methylene Blue (MB). The influence of affecting variables, such as initial MB dye concentration (2–8mg L−1), Cu(II)-MOF mass (0.01–0.03 mg), pH (3.0–9.0), and time of irradiation (30–90 min). The photocatalytic degradation efficiency was investigated by the central composite design (CCD) methodology. The results of CCD analysis for optimum values of variables revealed that Cu(II)-MOF mass was 0.025g, the initial concentration of MB was 3.51 mg L−1, pH was 4.50 and irradiation time was 75 min.Under the optimum conditions, the photocatalytic MB degradation percentage at the desirability function value of 1.0 was found to be 70%. In addition, the obtained R2 value of 0.97 in the regression analysis showed a high photocatalytic efficiency of the proposed method for MB degradation.

The plant-based extract can be used to synthesize silver nanoparticles (Ag NPs) as a reducing agent. In the present study, Oregano leaves’ extracts were extracted using ethanol to synthesize Ag NPs. The effects of different parameters such as the processing time, temperature, and stirring rate on the mean particle size, concentration, and zeta potential of the synthesized Ag NPs solutions were optimized using Response Surface Methodology (RSM). At the optimum condition, which includes processing time (30.48 min), temperature (70 ºC), and stirring rate (370.530 RPM), Ag NPs were obtained with 33 nm of the mean particle size, 76.109 ppm of concentration, and +17.2 mV of zeta-potential. In this condition, Ag NPs displayed high antibacterial activity against Gram-negative and Gram-positive bacteria. In addition, the maximum antioxidant activity of 11.7% was obtained at optimum synthesizing conditions.

The corrosion of aluminum beverage cans poses a significant industrial challenge that causes economic and health problems. However, there exists a requirement to gather scientific data that can offer knowledge to the food and packaging sectors, aiding in enhancing materials and reducing losses linked to this issue. This research examined how aluminum cans interacted with beverages using model solutions containing copper and chloride concentrations close to those typically found in beverages. This research highlights the influence of the temperature (20-50 °C), chloride concentration (25-1000 mg/L), and copper concentration (25-1000 µg/L) as independent variables on the corrosion of Al can in citric acid solution using Response surface methodology (RSM) with the Box–Behnken design (BBD). The input corrosion current density was assessed through potentiodynamic polarization tests conducted under variable conditions outlined in the design matrix. With p-values under 0.05 and good regression coefficients (R2), the (ANOVA) approach confirmed that the quadratic model developed was significant.  The RSM demonstrated a strong alignment between the predicted outcomes and the observed responses. The [Cl-] exhibited the most prominent and adverse impact on the dissolution of aluminum. The EIS graphs indicated that the corrosion reaction is primarily governed by the diffusion process.

In the present study, the applicability of PSF/Fe2O3 mixed matrix membrane synthesis for eliminating humic acid rapidly from aqueous solutions. Identical techniques, including FT-IR, XRD and SEM has been utilized to characterize this novel material. The investigation showed the applicability of PSF/Fe2O3 mixed matrix membrane as an available, suitable and low-cost adsorbent for proper deletion of humic acid from aqueous media. Also, the impacts of variables including initial humic acids (HAs) concentration (X1), pH (X2), adsorbent dosage (X3), sonication time (X4) came under scrutiny using central composite design (CCD) under response surface methodology (RSM). Additionally, the impacts of the pH of the solution, the amount of nanoparticles, concentration of humic acids (HAs), and contact time were investigated. The experiments have been designed utilizing response surface methodology. In this current article the values of 12 mg L-1, 0.03g, 7.0, 4.0 min were considered as the ideal values for humic acids (HAs) concentration, adsorbent mass, pH value and contact time respectively. The kinetics and isotherm studies proved the appropriateness of the second-order and Langmuir models for the kinetics and isotherm of the adsorption of humic acids (HAs) on the adsorbent. The adsorbent was proved to be recyclable for more than once. Since almost 99.5% of humic acids (HAs) was deleted with ideal adsorption capacities of 105 mg g−1 for humic acid (HAs). The overall results confirmed that PSF/Fe2O3 mixed matrix membrane could be a promising adsorbent material for humic acids (HAs) removal from aqueous solutions.

The applicability of Zeolitic Imidazolate-67 Modified by Fe3O4 Nanoparticles, was studied for eliminating butyl paraben dye from aqueous solutions. Identical techniques including BET, IR, XRD, and SEM have been utilized to characterize this novel material.  The impacts of variables including initial butyl paraben concentration (X1), pH (X2), adsorbent dosage (X3), and sonication time (X4) came under scrutiny using central composite design (CCD) under response surface methodology (RSM). Additionally, the impacts of the pH of the solution, the amount of nanoparticles, concentration of butyl paraben dye, and contact time were investigated. The experiments have been designed utilizing response surface methodology. In this current article the values of 10 mgL-1 , 0.03 g, 7.0, 4.0 min were considered as the ideal values for butyl paraben concentration, adsorbent mass, pH value and contact time respectively. The kinetics and isotherm studies proved the appropriateness of the second-order and Langmuir models for the kinetics and isotherm of the adsorption of butyl paraben on the adsorbent. The adsorbent was proved to be recyclable for more than once. Since almost 99.5% of butyl paraben was deleted with ideal adsorption capacities of 110 mgg−1 for butyl paraben in no time, therefore not only the short-time adsorption process was considered an advantage but also vantages in using Zeolitic Imidazolate-67 Modified by Fe3O4 Nanoparticles like being recyclable, safe, and cost-efficient made it a promising and powerful material for the aqueous solutions.

The applicability of Albizia Stem Bark Lebbeck Modified by Fe2(MoO4)3 nanocomposite, was studied for eliminating Methyl Violet dye from industrial wastewater. Identical techniques including (IR, XRD, and SEM) have been utilized to characterize this novel material. The impacts of variables including initial Methyl Violet concentration (X1), pH (X2), adsorbent dosage (X3), and sonication time (X4) came under scrutiny using central composite design (CCD) under response surface methodology (RSM). The values of 20 mgL-1, 0.03 g, 5.0, 3.0 min were considered as the ideal values for Methyl Violet concentration, adsorbent, pH, and contact time, respectively. Adsorption equilibrium and kinetic data were fitted with the Langmuir monolayer isotherm model and pseudo-second-order kinetics (R2: 0.999) with maximum adsorption capacity (120.4 mgg-1), respectively. Thermodynamic parameters (ΔG°: -9.26 kJ mol-1, ΔH°: -29.24 kJ mol-1, ΔS°: -131.49 kJ mol-1 K-1), also indicated Methyl Violet adsorption is feasible, spontaneous and exothermic. Overall results confirmed that Albizia Stem Bark Lebbeck Modified by Fe2(MoO4)3 nanocomposite is an effective adsorbent for removing the toxic dyes from an wastewater.

Non-edible oils are typically applied for multiple uses, especially biofuel production. But, finding new methods that can maximize the extraction of vegetable oils is urgently needed. In this work, natural enzymes present in kiwi fruit and ginger along with the ultrasound waves method were used to extract Bitter Almond Oil (BAO). Important factors affecting extraction were optimized using response surface methodology (Box-Behnken design). Under optimum conditions, the maximum extracted oil with an average of 62.1 wt.% oil/seed was extracted from the bitter almond kernel, which was only 0.87% less than the predicted value by the equation. The optimum conditions were: pH=4.74, Kiwi-Ginger juice to almond of 11.3 mL/g (22.6 mL ethanol), incubation temperature of 52 °C, ultrasonic power of 257 watts, and ultrasonic time of 38 min. The results confirmed the validity of the model. The applied technique in this investigation is economically cost-effective and highly efficient which can be widely used in the edible oil industry due to the absence of toxic and hazardous substances.

Potato peels contain valuable substances such as pectin extraction and the use of potato peels to produce pectin with appropriate properties can solve the biological problems resulting from these wastes in addition to value-added. The overall objective of this study is to investigate the effect of three variables including temperature (35, 65, and 95 °C), time (40, 120, and 200), and pH (1, 2, and 3) on the yield, galacturonic acid percentage and degree of pectin esterification extracted from the potato peels and optimization of the condition of extraction. The response surface method is used to optimize the conditions of extraction. The physicochemical properties of extracted pectin under optimum conditions were compared with commercial citrus and apple pectins by pectin flow behavior tests at different concentrations, FT-IR spectrum, and pectin molecular weight. The results of optimized single independent variables showed that the highest extraction yield of potato peel was 14.87% at 95 °C, 120 min time, and pH 1. The highest percentage of extracted galacturonic acid pectin in potato peel was 36.37% at 95 °C in 120 min and pH 1. The highest degree of esterification of extracted pectin from potato peel was 41.820% at 65 °C in 40 min time and pH 3.00. Simultaneous optimization of extracting pectin to achieve maximum yield was galacturonic acid with 100% desirability at 95 °C, 200 min time, and pH 1 in this condition, the yield was 15.23% and galacturonic acid was 38.0712%. The highest stability of extracted pectin emulsion from potato peel was observed at 4 °C on the first day. Also, the FT-IR results showed that the strong absorption between 3200-3500 cm-1 in the extracted pectin sample was related to the intracellular and extracellular vibration of the hydrogen bond in the galacturonic acid polymer. By increasing the concentration of pectin (0.1 to 2%) their viscosity was increased and the behavior of all samples was Newtonian and their flow index was about one. The molecular weight of extracted pectin from potato peel under optimum conditions was 53.46 kDa after 30 days of storage at 4 and 23 °C with emulsion stability 85.1 and 63.1, respectively. The results of this research showed that extracted pectin from potato peel can be introduced as a source of pectin to the market.

The applicability of the synthesized CM-β-CD-Fe3O4NPs as a novel adsorbent for eliminating Crystal Violet (CV) dye from aqueous media was investigated. This paper focuses on the development of an effective methodology to obtain the optimum removal conditions assisted by ultrasonic to maximize removal of (CV) dye onto CM-β-CD-Fe3O4NPs in aqueous solution using response surface methodology (RSM). This novel material was characterized by different techniques such as FT-IR, XRD and SEM. The influences of variables such as initial (CV) dye concentration (X1), pH (X2), adsorbent dosage (X3), sonication time (X4) investigated by central composite design (CCD) under response surface methodology. The process was empirically modeled to reveal the significant variables and their possible interactions. The optimization conditions were set as: 10.0 mg L-1, 6.0, 5 min and 0.025 g, for ultrasound time, pH, adsorbent mass, (CV) dye concentration respectively. Finally, it was shown that the adsorption of (CV) dye removal by adsorbent was at pH 6.0. This issue that the sorption of (CV) dye conforms to the pseudo-second-order rate equation and the Langmuir model explains equilibrium data was clearly proven. The maximum monolayer capacity (qmax) was found to be 100.0 mgg-1 for (CV) dye at optimum conditions. The application of Isotherms in obtaining the thermodynamic parameters like free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) of adsorption were confirmed. The exothermicity of the process was proven by negative value of (ΔGo, ΔHo and ΔSo) which showed the affinity of CM-β-CD-Fe3O4NPs synthesis for Crystal Violet (CV) dye deletion.

Hydrogen sulfide (H2S) is one of the polluting gases that enter the atmosphere during the natural gas processing of coal and furnace oil consumption. One of the best ways to remove H2S is to absorb H2s in the liquid phase and remove it biologically by sulfur bacteria in the liquid phase. This process considers the transfer of H2S and O2 between liquid and gas phases, biological oxidation of H2s to sulfate and elemental sulfur, and chemical oxidation to thiosulfate in the liquid phase. Due to the presence of sulfur bacteria in natural sulfur sources, the sulfur sources of sewage of Shahid Tondgooyan Oil Refining Co. in Tehran, Iran, and Mahallat Hot Spring in Iran, which contain sulfur compounds, were sampled in this study and were transferred to the laboratory for examination. Thiobacillusthioparus – one of the significant bacteria consuming sulfur compounds – was evaluated as a control sample. Further, the performance of bacteria in different culture conditions (carbon source and aeration conditions) was evaluated, and suitable conditions for their growth were determined. Sodium sulfide was used to create the sulfide medium. Next, sulfide consumption was evaluated by bacteria, and appropriate bacteria were selected. Finally, the production of sulfur during the process was evaluated using the ANOVA data analysis method. Then, the optimal points for sulfur production were predicted using the Response Surface Methodology (RSM)

In this research, KOH has been evaluated as a solid adsorbent for carbon dioxide (CO2) capture. The effect of pressure, temperature, and KOH loading on CO2 adsorption in a fixed-bed reactor were investigated. Response Surface Methodology (RSM) based on the central composite design (CCD) was used to evaluate the effects of operating parameters on adsorption capacity in order to achieve the optimum conditions. The experimental values of the responses were in decent agreement with the predicted result of regression models. Techniques such as Fourier Transform InfraRed (FT-IR) spectroscopy and X-ray diffraction (XRD) were used to study the consider KOH sorbent. The results show that CO2 adsorption is improved with the loading of 0.5 g of KOH. The maximum CO2 adsorption capacity was acquired for KOH at temperature 45°C and pressure 6 bars. The Freundlich model was found to be the best for fitting the adsorption of CO2 owing to the closeness of the R2 to unity. Furthermore, the kinetic study specified that the first-order model is well-fitted with the experimental data. Overall, the very high surface area of KOH adsorbent makes this adsorbent new promising material for CO2 capture.

In this study, feasibility of magnetic bentonite nanocomposite for removal of amoxicillin from wastewater samples was evaluated by high performance liquid chromatography (HPLC). Magnetic bentonite synthesized by co-precipitation of bentonite and Fe3O4 and used for removal of amoxicillin from water samples. Response surface methodology on central composition design (CCD) was applied for designing of experiment and building of model. Three factors including pH, adsorbent dose and temperature were studied and used for quadratic equation model to prediction of optimal points. By solving the equation and considering regression coefficient (R2 =0.98). The optimal points of main parameters were obtained as a pH of 4.68, the adsorbent dosage of 1.50 g and the temperature of 48.90 C. Results showed that three factor are significant on removal efficiency and experimental data are in good agreement with predicted data. Proposed methods were used to analysis of amoxicillin in three real samples

In this work, a novel chemically adsorbent based on Zn2Al-layered double hydroxide (LDH) that modified by indigo carmine (IC) (Zn2Al-LDH/IC) was synthesized. The chemical composition and morphology of the synthesized Zn2Al-LDH/IC were investigated using the X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy analysis. Response surface methodology (RSM) using the central composite design (CCD) is applied to optimize the adsorption process parameters for Cd(II) removal from the aqueous solution using a novel chemically modified nano Zn2Al-layered double hydroxide (Zn2Al-LDH/IC). The combined effect of adsorption parameters such as contact time, initial Cd(II) concentration, adsorbent amount and initial pH of solution were studied. The results obtained by ANOVA analysis displayed the relative significance of the process parameters in the adsorption process. The optimum conditions to remove Cd(II) from aqueous solution were at the initial Cd(II) concentration of 52 mg/L-1, pH 4.13, the adsorbent dose 0.06 g, temperature of 36.5 °C and contact time 36 min. In optimum conditions, high adsorption efficiency and maximum adsorption capacity were 47.3% and 6.11 mg/g, respectively.  Adsorption of Cd(II) by nano Zn2Al-LDH/IC could be well examined with Langmuir and Freundlich isotherms and the pseudo second-order kinetic model was fitted to the adsorption kinetic data. Furthermore, the thermodynamic data exhibited that the adsorption process of Cd(II) by nano Zn2Al-LDH/IC was spontaneously and exothermic.

MIL-53(Fe) with huge porosity has been synthesized by microwave radiation in the different ‎conditions: various powers (80, 100W) and time (5, 10 min). Nano-sized crystals were ‎characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier ‎transform infrared spectroscopy (FTIR) and specific surface area analysis. After performing the characterization, MIL-53(Fe)-1 with the best porous structure for Pb (II) and Cd (II)‎ removal was used for all tests from aqueous solution. The best condition for synthesis was 5 min and 80 W. Then the best porous structure was selected for removal of Pb (II) / Cd (II) from aqueous solution. The ‎response surface methodology (RSM) based on central composite design (CCD) was applied to ‎optimize the removal capacity. In these experimental designs, four independent variables were studied and the best condition was evaluated as ‎‎pH(in the range of 6-8), temperature (40-50◦C), contact time (50 min), and adsorbent amount (0.1-0.3 g.L-1). The removal efficiency and ‎capacity of MIL-53(Fe) for Pb (II) and Cd (II) was further surveyed. Langmuir equation was the ‎best isotherm to describe the adsorption manner of Pb (II) and Cd (II) ions (qmax values ( 178.57 and 714.28 mg g−1) for Pb (II) and Cd (II)). The adsorption ‎process was confirmed by a pseudo-second-order kinetic pattern. The result of thermodynamic ‎studies displayed that the sorption process was spontaneous and exothermal.

Hydrophobic magnetic silica aerogel was used as a support to immobilize Candida rugosa lipase by adsorption method. Physical and chemical properties of the support and immobilized lipase were determined by Field Emission Scanning Electron Microscope (FESEM), Brunauer–Emmett–Teller (BET) analysis and Fourier Transform InfraRed (FT-IR) spectroscopy and the results showed that the lipase was successfully immobilized onto the support. Biodiesel production from sunflower oil using immobilized lipase was investigated. Response Surface Methodology (RSM) was employed to evaluate the effect of process variables namely methanol/oil molar ratio (4:1-6:1), enzyme concentration (4-10 % mass fraction of oil) and water concentration (3-10 % mass fraction of oil) on biodiesel yield and predict the optimal reaction conditions. A second-order regression model with a high coefficient determination value (R2= 0.99) was fitted to predict the response as a function of reaction parameters. The results indicated that optimum values for methanol/oil molar ratio, enzyme concentration, and water concentration were obtained at 4.5:1, 9.4% and 7.4 %, respectively, in which biodiesel yield was predicted at 72.3%. As the difference between the experimental and predicted values were shown as non-significant, the response surface model employed could be considered as adequate.

: Unwanted water production from oil and gas reservoirs is a serious problem for producers. Preformed particle gel (PPG) treatment is a benefit approach to control excess water production. Swelling percentage of PPG samples in saline water is a key factor affecting the efficiency of the water conformance process. In this study, an efficient series of PPGs were synthesized and their swelling behaviors were studied. The design of experiments (DOE) software was used to design synthesis experiments and optimum swelling percentage of PPGs in BaCl2 salt solution. Results showed that the optimized range of the dominant factors including mole ratio of acrylamide (AAm) to acrylic acid (AA), the mole percentage of N,N'-methylenebisacrylamide (MBA) and time were found to be 6.8 to 7.4, 4.2 to 4.5 percent and 179.8 to 180 min, respectively. Additionally, PPGs had the maximum swelling percentage of 529% in the optimum conditions. In the end, for the first time, an empirical correlation was proposed by the software that predicts the swelling percentage of PPGs in BaCl2 salt solution, which had good compatibility with the laboratory data.

Green chemistry - also called sustainable chemistry - as the cost-effective and environmentally friendly techniques have been gaining more attention recent years. Here, we introduced a fast, non-toxic and sustainable method to synthesize Ag nanoparticles. Various parameters are involved in the bio-synthesis of Ag nanoparticles/multi-walled carbon nanotubes (Ag/MWf-CNT) composites, including silver nitrate concentration, initial pH, temperature, CNT concentration, agitation time, biomass and stirring rate. The Plackett–Burman Design (PBD) approach indicated that the initial pH, the carbon nanotube concentration and the weight of biomass are the major effects of the Ag/MWf-CNT biosynthesis. A quadratic polynomial model was developed using Central Composite Design (CCD) to statistically evaluate the effect of the initial
pH (3.5-7), the carbon nanotubes concentration (0.2-1 g/L) and the weight of wet biomass (6-16 g) on the response- reduction percentage of Ag ions. The significant factors and their interactions in the biosynthesis process were examined by means of analysis of variance (ANOVA). The results showed that the wet biomass weight has the most significant effect on the response compared to the other variables. Additionally, the model predicted that up to 89% of Ag reduction to Ag nanoparticles were obtained at the optimum range conditions– weight of biomass 13 g, the initial pH range 5.5-6.2 and concentration of carbon nanotubes 0.6 g/L.