Wilson Experimental Design Research Articles

Green Extraction of Carotenoids from Tomato By-products Using Sodium Dodecyl Sulphate

AbstractTomato peel by-products contain high levels of lycopene, which has traditionally been extracted using organic solvents. This research focuses on the optimisation of a sustainable method to obtain a lycopene-rich extract using the biodegradable anionic surfactant sodium dodecyl sulphate (SDS). A Plackett–Burman experimental design was used to investigate the effect of seven factors on the extraction of carotenoids from tomato peels using sodium dodecyl sulphate (SDS volume and concentration, homogenisation intensity and time, sonication phase, extraction time and ultracentrifugation intensity). Based on the responses of total carotenoid extraction, the SDS volume, the use of ultrasound and the extraction time significantly influenced the extraction yield and were selected for optimisation using a Box–Wilson experimental design. The final green extraction protocol (1 g sample + 11.9 ml SDS 0.3%, homogenisation at 13,500 rpm for 2 min, ultrasound phase, agitation for 8.2 h and ultracentrifugation) was selected after quantification of total carotenoids by UV–VIS and HPLC-DAD. Finally, we used nuclear magnetic resonance to demonstrate a high lycopene purity in the carotenoid extract obtained. Furthermore, using transmission electron microscopy, we observed the presence of intact chromoplasts in the extract, protecting the carotenoids from the exposure to external agents. Thus, this work reports an optimised method for the sustainable extraction of carotenoids and demonstrates the viability of the degradable solvent SDS for the extraction of liposoluble bioactive compounds, like carotenoids and mainly lycopene. The lycopene extract could be used for the technological and nutritional enrichment of new foods and/or the design of nutraceuticals.

The Variance of the Polypropylene α Relaxation Temperature in iPP/a-PP-pPBMA/Mica Composites

By considering that the α relaxation related to the glass to rubber transition (obtained by dynamic mechanical analysis) of isotactic polypropylene (iPP) can be identified with the thermal history of the material (and so, with the processing step), this work deals with the changes in this transition temperature (Tα) in polypropylene/mica composites caused by the mutual effect of the other components (mica and interfacial additive). Here, the additive used is a p-phenylen-bis-maleamic grafted atactic polypropylene (aPP-pPBMA) obtained from polymerization wastes (aPP) by the authors. This additive contains 5.0·10−4 g.mol−1 (15% w/w) grafted pPBMA. In essence, this article has two different objectives: (1) To observe and discuss the changes in Tα of the polymer matrix (iPP) caused by the combined effect of the other components (mica and aPP-pPBMA); and (2) predicting the values for Tα in terms of both aPP-pPBMA and mica content for whatever composition in the experimental space scanned. This task was undertaken by employing a Box–Wilson experimental design assuming the complex character of the interactions between the components of the iPP/aPP-pPBMA/mica system, which define the ultimate properties of the composite.

Sustainable extraction of hazardous metals from crystal glass waste using biodegradable chelating agents

Extraction of hazardous metals from dumped crystal glass waste was investigated for site decontamination and resource recovery. Mechanically activated glass waste was leached with biodegradable chelating agents of ethylenediamine-N,N′-disuccinic acid (EDDS) and nitrilotriacetic acid (NTA), where the concentration and reaction time were determined by using Box–Wilson experimental design. Hazardous metals of lead (Pb), arsenic (As), antimony (Sb) and cadmium (Cd) with concentrations higher than regulatory limits were extracted wherein the extraction yield was found to vary Pb > Sb > As > Cd. Extraction was influenced more by type and concentration of chelator rather than by reaction time. A maximum of 64% of Pb could be extracted by EDDS while 42% using NTA. It is found that increase of chelator concentrations from 0.05 M to 1 M did not show improved metal extraction and the extraction improved with reaction time until 13 h. This study provides sustainable alternative for treating hazardous glass waste by mechanical activation followed by extraction using biodegradable chelator, instead of acid leaching.Graphical abstract

On the Combined Effect of Both the Reinforcement and a Waste Based Interfacial Modifier on the Matrix Glass Transition in iPP/a-PP-pPBMA/Mica Composites.

This work deals with the changes of the glass transition temperature (Tg) of the polymer in polypropylene/mica composites due to the combined and synergistic effect of the reinforcement and the interfacial modifier. In our case, we studied the effect on Tg of platy mica and an interfacial modifier with p-phenylen-bis-maleamic acid (pPBMA) grafted groups onto atactic polypropylene (aPP-pPBMA). This one contains 5.0 × 10−4 g·mol−1 (15% w/w) grafted pPBMA and was previously obtained by the author’s labs by using industrial polymerization wastes (aPP). The objective of the article must be perceived as two-fold. On one hand, the determination of the changes in the glass transition temperature of the isotactic polypropylene phase (iPP) due to both the reinforcement and the agent as determined form the damp factor in DMA analysis. On the other hand, forecasting the variation of this parameter (Tg) as a function of both the interfacial agent and reinforcement content. For such purposes, and by assuming the complex character of the iPP/aPP-pPBMA/Mica system, wherein interaction between the components will define the final behaviour, a Box–Wilson experimental design considering the amount of mica particles and of interface agent as the independent variables, and the Tg as the dependent one, has been used. By taking in mind that the glass transition is a design threshold for the ultimate properties of parts based in this type of organic–inorganic hybrid materials, the final purpose of the work is the prediction and interpretation of the effect of both variables on this key parameter.

Optimization of sulfuric acid leaching of roasted chalcopyrite concentrate with Box–Wilson experimental design

Chalcopyrite (CuFeS2) is commonly used ore in production of copper, but leaching of this ore is very slow and inefficient due to “passivation” during leaching at atmospheric conditions. In this study, in order to overcome drawbacks of the passivation layers, the concentrate supplied from Eti Bakir A.S. Kure Plant in Turkey was roasted at 600 °C for 1 h and after leached. Box–Wilson procedure of statistical experimental design was utilized to identify the effects of significant leaching variables for instance leaching time (X1; 10–120 min), solid/liquid ratio (X2; 0.01–0.20), and H2SO4 concentration (X3; 0.01–1.00 M) on Cu extraction (%) from roasted concentrate and was tried to be optimized. The coefficients of response functions have been calculated by regression analysis, and the estimates have been found to be well in line with the experimental outcomes. The optimal leaching parameters, time, solid/liquid rate and H2SO4 concentration were determined as 115 min, 0.116, and 0.71 M, respectively, and the highest Cu extraction (%) value was calculated as 92.45%.

Aluminum ASA 6061 Anodizing Process by Chromic Acid Using Box–Wilson Central Composite Design: Optimization and Corrosion Tendency

The behavior of anodic porous alumina film formed on an aluminum surface by anodizing in chromic acid solutions was optimized using Box–Wilson experimental design. The film thickness was correlated as a function of temperature, acid concentration, applied voltage, and time. A mathematical model was suggested and optimized. Results of coating thickness indicate that both temperature and time play an important role in the anodizing process. The interaction effect of variables on the film thickness is less pronounced compared with the effect of the main variables. Optimum film thickness obtained during the anodizing process was 10.43 µm at the optimum value of temperature (45 °C) and time (68 min). The polarization measurement of anodized aluminum ASA 6061 in chromic acid shows a high corrosion resistance in the presence of coating. The results confirmed by using surface morphology investigations.

The Role of a Succinyl Fluorescein-Succinic Anhydride Grafted Atactic Polypropylene on the Dynamic Mechanical Properties of Polypropylene/Polyamide-6 Blends at the Polypropylene Glass Transition.

The present article adequately supports a twofold objective. On one hand, the study of the dynamic mechanical behavior of polypropylene/polyamide-6 blends modified by a novel compatibilizer was the objective. This was previously obtained by chemical modification of an atactic polypropylene polymerization waste. On the other hand, the accurate predictions of these properties in the experimental space scanned was the objective. As a novelty, this compatibilizer contains grafts rather than just maleated ones. Therefore, it consists precisely of an atactic polymer containing succinic anhydride (SA) bridges and both backbone and terminal grafted succinyl-fluorescein groups (SFSA) attached to the atactic backbone (aPP-SFSA). Therefore, it contains 6.2% of total grafting (2.5% as SA and 3.7% as SF), which is equivalent to 6.2 × 10−4 g·mol−1. This interfacial agent was uniquely designed and obtained by the authors themselves. Essentially, this article focuses on how the beneficial effect of both PA6 and aPP-SFSA varies the elastic (E’) and the viscous (E’’) behavior of the iPP/aPP-SFSA/PA6 blend at the iPP glass transition. Thus, we accurately measured the Dynamic Mechanical Analysis (DMA) parameters (E’, E’’) at this specific point considering it represents an extremely unfavorable scenario for the interfacial modifier due to mobility restrictions. Hence, this evidences the real interfacial modifications caused by aPP-SFSA to the iPP/PA6 system. Even more, and since each of the necessary components in the blend typically interacts with one another, we employed a Box–Wilson experimental design by its marked resemblance to the “agent-based models”. In this manner, we obtained complex algorithms accurately forecasting the dynamic mechanical behavior of the blends for all the composition range of the iPP/aPP-SFSA/PA6 system at the glass transition of iPP.

Industrial waste origin succinic anhydride‐grafted atactic polypropylene as compatibilizer of full range polypropylene/polyamide 6 blends as revealed by dynamic mechanical analysis at the polypropylene glass transition

This work deals with a dynamic mechanical analysis (DMA) study on the effect of a novel interfacial agent containing maleated grafts on an industrial waste origin atactic polypropylene. This contains 3% of bridge‐, backbone‐, and terminal‐grafted succinic anhydride groups (aPP‐SA/SA). By considering a polymer blend as a special case of composite where the dispersed phase is mobile, it is assumed that both the amounts of polyamide 6 (PA6) and the interfacial agent (aPP‐SA/SA) cause changes in the glass transition temperature of the polypropylene phase in the blend. In this work, we have used DMA parameters to evidence the real interfacial modifications caused by the presence of aPP‐SA/SA in the isotactic polypropylene (iPP)/PA6 system at the iPP glass transition temperature on the basis that this is an unfavorable scenario for the action of aPP‐SA/SA. Since each component of the blend is interacting with each other, and to include the influence of the dispersed phase, it is possible to use a Box–Wilson experimental design model by resembling the so‐called “agent based models” to obtain algorithms forecasting the dynamic mechanical parameters (storage, E’, and loss moduli, E”) at the glass transition of iPP, in all the composition range of whatever iPP/PA6/aPP‐SA/SA‐modified blend. POLYM. ENG. SCI., 59:2458–2466, 2019. © 2019 Society of Plastics Engineers

Application of Box Wilson experimental design method for removal of acid red 95 using ultrafiltration membrane

The applicability of the ultrafiltration process for color removal from dye-containing water has been examined in this study. The optimization of major process variables, such as dye concentration, chitosan concentration and transmembrane pressure on permeate flux and color removal efficiency was investigated. To find the most appropriate results for the experiment, the Box-Wilson experimental design method was employed. The results were correlated by a response function and the coefficients were determined by regression analysis. Permeate flux variation and color removal efficiency determined from the response functions were in good agreement with the experimental results. The optimum conditions of chitosan concentration, dye concentration and pressure were 50 mg/l, 50 mg/l and 3 bars, respectively for the highest permeate flux. On the other hand, optimum conditions for color removal efficiency were determined as 50 mg/l of dye concentration, 50 mg/l of chitosan concentration and 1 bar of pressure.

Adsorption and kinetics behavior of kiwi juice as a friendly corrosion inhibitor of steel in acidic media

PurposeThis paper aims to study the corrosion inhibition of mild steel in 2.5 M HCl solution by kiwi juice at different temperatures, inhibitor concentration and immersion times.Design/methodology/approachBox–Wilson experimental design is used for runs distribution and the corrosion rate values are evaluated by weight loss technique.FindingsCorrosion rate increased with temperature according to Arrhenius equation, and the inhibitor adsorbed according to Langmuir adsorption isotherm. Second-order polynomial model is used for data fitting. The optimum conditions were estimated with maximum inhibitor efficiency of 96.1 per cent. Fourier transform infrared analysis showed that the peaks correspond to phenols, and quercitine is the main component. Microstructural, hardness and theoretical quantum studies are also performed.Originality/valueThis is one of the first steps in the direction of understanding the corrosion control problems from different views. Kinetics, surface morphology, optimization and mathematical views are taken in to account.

The effect of a p‐phenylen‐bis‐maleamic acid grafted atactic polypropylene interfacial agent on the dynamic‐mechanical properties of iPP/Mica composites measured at the polymer transitions

This work deals with the study of the evolution (with temperature) of the in‐phase (E′) and the out‐of‐phase (E″) moduli of polypropylene/mica composites with improved interfacial interactions by the presence of an industrial waste based interfacial modifier named as p‐phenylen‐bis‐maleamic (pPBMA) acid grafted atactic polypropylene (aPP–pPBMA). This additive contains 15% w/w grafted pPBMA (5.0·10−4 g mol−1) obtained from polymer industrial wastes in the Polymer Engineering Group (GIP) labs. The purpose of the work is twofold. One, dynamic mechanical analysis (DMA) has been used to evidence the improvement in properties due to the interfacial modifications by the addition of the novel interfacial modifier (aPP–pPBMA). And two, to obtain a mathematical model to predict the DMA moduli of the composite at α and β transition temperatures. So, a Box–Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables, and the modulus as the dependent ones at each transition was used. Thus, the final purpose of the work is obtaining forecasts for the DMA parameters as a function of the composite components and of the type of temperature dependent relaxation phenomena taking place. POLYM. ENG. SCI., 57:746–755, 2017. © 2017 Society of Plastics Engineers

Pretreatment of Cheese Whey Effluent Using a Microfiltration Process: A Statistical Design Approach

Pretreatment of cheese whey effluent from the dairy industry using chitosan as a coagulant and a microfiltration process such as a solid/liquid separator was investigated in this study. The optimization of major process variables, such as chitosan concentration, transmembrane pressure, and operation time on permeate flux and COD removal efficiency was investigated. To find the most appropriate result for the experiment, The Box–Wilson experimental design was employed. Response function coefficients were determined by regression analysis of experimental data and predictions were found to be in good agreement with the experimental results. The optimal concentration of chitosan and transmembrane pressure was 5 mg/L and 2 bar pressure for maximum permeate flux with a 23.0 L/m2.h flux value, respectively. On the

Functionalization of carbon nanotubes by water plasma

Multiwall carbon nanotubes grown by plasma enhanced chemical vapour deposition were functionalized by H2O plasma treatment. Through a controlled functionalization process of the carbon nanotubes (CNTs) we were able to modify and tune their chemical reactivity, expanding the range of potential applications in the field of energy and environment. In particular, different oxygen groups were attached to the surfaces of the nanotubes (e.g. carboxyl, hydroxyl and carbonyl), which changed their physicochemical properties. In order to optimize the main operational parameters of the H2O plasma treatment, pressure and power, a Box–Wilson experimental design was adopted. Analysis of the morphology, electrochemical properties and functional groups attached to the surfaces of the CNTs allowed us to determine which treatment conditions were suitable for different applications. After water plasma treatment the specific capacitance of the nanotubes increased from 23 up to 68 F g−1 at a scan rate of 10 mV s−1.

Effects of Fenton Pre‐Treatment on Waste Activated Sludge Properties

AbstractFenton process was investigated for the purpose of biological sludge disintegration. The Box–Wilson experimental design was employed to evaluate the effects of major process variables (Fe(II) and H2O2 concentrations) on both disintegration and dewatering performance of sludge. Results showed that 4 g Fe(II)/kg total solids (TSs) and 60 g H2O2/kg TS are efficient for floc disintegration. Fenton pre‐treatment enhanced the biodegradability of sludge. For 4 g Fe(II)/kg TS and 60 g H2O2/kg TS, 19.4% higher methane production was achieved compared to raw sludge in biochemical methane potential assay. Fenton pre‐treatment resulted in the release of organic sludge components into the liquid phase. For 4 g Fe(II)/kg TS and 60 g H2O2/kg TS, dissolved organic carbon and total nitrogen in sludge's supernatant increased by 75.74 and 60.60%, respectively. Fenton pre‐treatment enhanced the filterability of sludge and it can be applied for conditioning purpose before mechanical dewatering units.

Application of Box–Wilson experimental design method for 2,4-dinitrotoluene treatment in a sequential anaerobic migrating blanket reactor (AMBR)/aerobic completely stirred tank reactor (CSTR) system

A sequential aerobic completely stirred tank reactor (CSTR) following the anaerobic migrating blanket reactor (AMBR) was used to treat a synthetic wastewater containing 2,4-dinitrotoluene (2,4-DNT). A Box–Wilson statistical experiment design was used to determine the effects of 2,4-DNT and the hydraulic retention times (HRTs) on 2,4-DNT and COD removal efficiencies in the AMBR reactor. The 2,4-DNT concentrations in the feed (0–280mg/L) and the HRT (0.5–10 days) were considered as the independent variables while the 2,4-DNT and chemical oxygen demand (COD) removal efficiencies, total and methane gas productions, methane gas percentage, pH, total volatile fatty acid (TVFA) and total volatile fatty acid/bicarbonate alkalinity (TVFA/Bic.Alk.) ratio were considered as the objective functions in the Box–Wilson statistical experiment design in the AMBR. The predicted data for the parameters given above were determined from the response functions by regression analysis of the experimental data and exhibited excellent agreement with the experimental results. The optimum HRT which gave the maximum COD (97.00%) and 2,4-DNT removal (99.90%) efficiencies was between 5 and 10 days at influent 2,4-DNT concentrations 1–280mg/L in the AMBR. The aerobic CSTR was used for removals of residual COD remaining from the AMBR, and for metabolites of 2,4-DNT. The maximum COD removal efficiency was 99% at an HRT of 1.89 days at a 2,4-DNT concentration of 239mg/L in the aerobic CSTR. It was found that 280mg/L 2,4-DNT transformed to 2,4-diaminotoluene (2,4-DAT) via 2-amino-4-nitrotoluene (2-A-4-NT) and 4-amino-2-nitrotoluene (4-A-2-NT) in the AMBR. The maximum 2,4-DAT removal was 82% at an HRT of 8.61 days in the aerobic CSTR. The maximum total COD and 2,4-DNT removal efficiencies were 99.00% and 99.99%, respectively, at an influent 2,4-DNT concentration of 239mg/L and at 1.89 days of HRT in the sequential AMBR/CSTR.

Application of Box–Wilson experimental design method for the solar photocatalytic degradation of textile dyestuff with Fe(III)/H 2O 2/solar UV process

As an advanced oxidation treatment, Fe(III)/H 2O 2/solar UV process was applied to an azo dye, Reactive Blue 19 (RB19), a widely used textile dyestuffs in the Turkish textile industry. A solar photocatalytic reactor was used for the advanced oxidation. Box–Wilson experimental design method was employed to optimize the wastewater flowrate, oxidant and catalyst concentrations as significant factors for maximum decolorization and organic matter removal. Color and organic matter removals were monitored throughout the operation period. Complete decolorization ( E = 100%) was obtained for the strong dye solution with 50 mg/L dyestuff concentration with the addition of 2677 mg/L H 2O 2 and 0.5 mM Fe(III) at 10 L/h flowrate after 8 h of exposure to the solar irradiation. The maximum reduction in the total organic carbon (TOC) concentration was 90% under the same operating conditions.

Improving Knowledge of Garlic Paste Greening through the Design of an Experimental Strategy

The furthering of scientific knowledge depends in part upon the reproducibility of experimental results. When experimental conditions are not set with sufficient precision, the resulting background noise often leads to poorly reproduced and even faulty experiments. An example of the catastrophic consequences of this background noise can be found in the design of strategies for the development of solutions aimed at preventing garlic paste greening, where reported results are contradictory. To avoid such consequences, this paper presents a two-step strategy based on the concept of experimental design. In the first step, the critical factors inherent to the problem are identified, using a 2(III)(7-4) Plackett-Burman experimental design, from a list of seven apparent critical factors (ACF); subsequently, the critical factors thus identified are considered as the factors to be optimized (FO), and optimization is performed using a Box and Wilson experimental design to identify the stationary point of the system. Optimal conditions for preventing garlic greening are examined after analysis of the complex process of green-pigment development, which involves both chemical and enzymatic reactions and is strongly influenced by pH, with an overall pH optimum of 4.5. The critical step in the greening process is the synthesis of thiosulfinates (allicin) from cysteine sulfoxides (alliin). Cysteine inhibits the greening process at this critical stage; no greening precursors are formed in the presence of around 1% cysteine. However, the optimal conditions for greening prevention are very sensitive both to the type of garlic and to manufacturing conditions. This suggests that optimal solutions for garlic greening prevention should be sought on a case-by-case basis, using the strategy presented here.

Use of experimental design method to investigate metal ion effects in yeast fermentations

AbstractThe dependence of ethanol production by fermentation using Saccharomyces cerevisiae 251 TP(3‐2) on zinc, sodium and potassium ion concentration was studied with the use of a statistical experimental design. The parameters of the ethanol concentration model proposed on the basis of the Box–Wilson experimental design method were evaluated using the experimental data. Comparison of the predicted values from the model with the experimentally observed values showed that the model is a good fit. From analysis of the model equation it was seen that zinc, sodium and potassium ion concentrations have significant main effects on ethanol production but there were no interactive effects of the ions. Using the developed model, the maximum ethanol concentration of 4.19% (v/v) was obtained when potassium, sodium and zinc concentrations were 7900, 930 and 3.04 mg L−1, respectively. Copyright © 2007 Society of Chemical Industry

Prediction of radio frequency power effect on silicon nitride deposition using a genetic algorithm based neural network

Deposition rate of silicon nitride films was modelled using a neural network in conjunction with Box—Wilson experimental design. The films were deposited by a plasma enhanced chemical vapour deposition system. A neural network model was constructed and tested with 33 and 12 experiments respectively. Model prediction performance was significantly improved by applying genetic algorithm to training factor optimisation. To qualitatively estimate deposition mechanisms with the parameters, several plots were generated from the model and emphasis was placed on the investigation of the radio frequency power effect on the deposition rate under various plasma conditions. An increase in the deposition rate with increasing power was ascribed to more Si deposition near the reaction surface. The SiH4 effect was the most complex depending on the powers. In contrast, the power effect was insensitive to the variations in N2 flow rate. The power effect at high pressure was attributed to increased concentration of Si radicals in the gas phase. A comparison with a refractive index model facilitated to infer deposition mechanisms.

Application of Box–Wilson experimental design method for the photodegradation of bakery's yeast industry with UV/H 2O 2 and UV/H 2O 2/Fe(II) process

Decolorization and mineralization of bakery's yeast industry effluent by photochemical advanced oxidation processes (AOPs) utilizing UV with hydrogen peroxide and Photo-Fenton, were investigated in a laboratory scale photo-reactor equipped with a 16 W low-pressure mercury vapor lamp. The Box–Wilson experimental design method was employed to evaluate the effects of major process variables (e.g. pH, oxidant dose, and irradiation time) on the decolorization efficiency. Response function coefficients were determined by regression analysis of the experimental data and prediction results agreed with the experimental results. The optimum hydrogen peroxide concentration and irradiation time were found to be 5 mM and 50 min at pH 3, respectively, for UV/H 2O 2 process. In the Photo-Fenton process application, maximum decolorization efficiency (96.4%) was obtained at the optimum reaction conditions that were 100 mM H 2O 2 and 1 mM Fe(II) doses at pH 3, and 10 min of irradiation time.