Factorial Experimental Design Approach Research Articles

Screening significant properties of macro-fiber composite laminate substrate anisotropy with viscoelastic and thermal considerations at the quasi-static level

A macro-fiber composite (MFC) is a class of smart material actuator that employs piezoceramic fibers to extend or contract under an applied electric field. When embedded on a thin substrate, actuated MFCs induce surface pressure, resulting in out-of-plane motion. Design characteristics of the substrate, such as anisotropy, give rise to unique bend/twist behavior. Previous studies on MFC applications have focused on optimizing patch location in relation to the local design to achieve optimal bend/twist motion. However, the resolution to these approaches is restricted to the design space of the application, presenting an absence in piezoelectric laminate design intuition. This research aims to streamline the initial optimization process by analyzing the significant material properties associated with substrate design. To accomplish this, a viscoelastic piezoelectric plate theory model is developed to accurately capture the displacement behavior of the MFC laminate for any given substrate design. Experimental data is used to validate and refine the model, ensuring it closely represents real-world physics. A 2k fractional factorial design of experiments approach is used to identify significant substrate properties per MFC laminate configuration, assigning each material property a two-level coding system. Three configurations are observed, with each exhibiting distinct significant properties and effects compared to others. Furthermore, the study explores the impact of thermal factors on substrate behavior for these MFC laminates, highlighting how significant properties can be temperature dependent. The contributions to the kinematic response due to substrate property perturbation varies uniquely per material property and MFC laminate configuration. Statistical evidence supports the notion that the hysteretic behavior of a material is unaffected by thermal influences and is solely determined by the elastic constants of the substrate. The maximum remanent hysteretic response is shown to be proportional to the maximum actuation response at near room temperature.

Effects of process parameters and scan strategy on the microstructure and density of stainless steel 316 L produced via laser powder bed fusion

The ability to produce reliable and reproducible components from 316 L using additive manufacturing is crucial to serve the need for customization, on-demand manufacturing and reduced lead times for various industries. Laser powder bed fusion is becoming widely accepted as a versatile additive manufacturing technique capable of producing near defect-free components with tailored microstructures and mechanical properties. However, despite the recent progress in process parameter selection and optimization, even a small change in any of the laser parameters, equipment and feedstock powder characteristics can influence the microstructure and subsequently the mechanical properties of the fabricated parts. The purpose of this work is to tackle the process optimization challenge through, a full factorial design of experiments approach, to systematically assess the widely adopted energy density factor to evaluate the density of the final component. A statistical approach was also followed to evaluate potential plastic anisotropy in different samples produced with various energy densities and scan strategies. Density measurements indicated that beyond laser power and scan speed, the interaction effects of the aforementioned parameters with the layer thickness and the powder size distribution have a significant effect on the sample. Microstructural features such as melt pools, grains and crystallographic texture were characterized against a range of volumetric energy densities and scan strategies represented by different angles of rotation between successive layers. Smaller angles of rotation per layer were found to decrease texture anisotropy and suppress the formation of keyhole porosity in finer and more homogenous microstructures. The assessment of plastic anisotropy in the produced samples was evaluated using microhardness measurements on all three orthogonal planes of the samples. The hierarchical microstructure of laser powder bed fusion materials induces several strengthening mechanisms, that can simultaneously be activated depending on the loading scenario, location and plane.

Can the Incorporation of Different Concentrations of Buriti ( Mauritia flexuosa ) Oil Change the Rheological Properties of Filmogenic Solutions? A Factorial Experimental Design Approach

Background: Buriti (Mauritia flexuosa) oil has high economic potential because it contains monounsaturated and polyunsaturated fatty acids with high antioxidant potential and high carotenoid content, making it an excellent source of pro-vitamin A. Objective: The objective of this work was to evaluate the rheological properties of filmogenic solutions incorporated with different buriti oil concentrations. Methods: Buriti oil (0.15 to 0.45% w/v) and emulsifier (Tween®20) (0.02 to 0.04% w/v) were combined using a factorial experimental design 22 with 3 central points for the preparation of filmogenic solutions with cassava starch (3%, w/v) and glycerol (0.06%, w/v). Rheological properties, static and centrifugation emulsion stabilities, and pH value of filmogenic solutions were evaluated. Results: Filmogenic solutions with lower emulsifier concentration showed increased flow resistance and non-Newtonian and pseudoplastic behavior (n<1). Central point formulation (E, F, and G) remained stable (no particle agglomeration) throughout the test period, as well as pH value close to neutrality. In centrifugation stability index at 3500 rpm, only formulation C did not show phase separation. Conclusion: It was possible to develop a mixture of a filmogenic solution containing buriti oil that could be applied as an eco-friendly coating in food.

Tavaborole microemulsion: New strategy for the targeted treatment of onychomycosis

The targeted treatment of onychomycosis becomes a major concern nowadays for onychologist considering the limited permeability of the drug formulation at the nail site due to the number of factors such as complex barrier of keratin structure inside the nail layer, drug-keratin binding properties, as well as lack of availability of promising drug delivery system. In the present study, tavaborole-loaded novel microemulsion and its gel formulation was developed, optimized, and evaluated for the targeted treatment of onychomycosis. The microemulsion formulation was designed and developed using a 32 factorial experimental design approach. The optimized microemulsion formulation consisting of tavaborole (2.5%w/w), glyceryl caprylate/caprate (7.8%w/w), polyethylene glycol-8 caprylate/capric glycerides (21.45%w/w), diethylene glycol monoethyl ether (21.45%w/w) and demineralized water (46.80%w/w) was converted to gel using carbopol® 934P (0.5%w/w). In the ex-vivo bovine hoof membrane model permeation study, the optimized microemulsion formulation exhibited higher drug permeation (116.21 ± 9.75 μg/cm2) and followed the first-order release kinetics mechanism. The in-vitro nail clipping study demonstrated enhanced penetration of tavaborole (0.872 ± 0.019 μg/mg) from optimized microemulsion formulation. It also exhibited improved antifungal activity against dermatophytes species such as Trichophyton rubrum (2.56 ± 0.086 cm), Trichophyton mentagrophytes (3.13 ± 0.097 cm), and Candida albicans (3.63 ± 0.103 cm). The microemulsion formulation did not reveal any toxic and detrimental effects of excipients on nail cells in VERO cell lines cytotoxicity study. Thus, tavaborole loaded microemulsion can be considered as a potential formulation for topical onychomycosis therapy.

Influence of Bifilm Defects Generated during Mould Filling on the Tensile Properties of Al–Si–Mg Cast Alloys

Entrapped double oxide film defects are known to be the most detrimental defects during the casting of aluminium alloys. In addition, hydrogen dissolved in the aluminium melt was suggested to pass into the defects to expand them and cause hydrogen porosity. In this work, the effect of two important casting parameters (the filtration and hydrogen content) on the properties of Al–7 Si–0.3 Mg alloy castings was studied using a full factorial design of experiments approach. Casting properties such as the Weibull modulus and position parameter of the elongation and the tensile strength were considered as response parameters. The results suggested that adopting 10 PPI filters in the gating system resulted in a considerable boost of the Weibull moduli of the tensile strength and elongation due to the enhanced mould filling conditions that minimised the possibility of oxide film entrainment. In addition, the results showed that reducing the hydrogen content in the castings samples from 0.257 to 0.132 cm3/100 g Al was associated with a noticeable decrease in the size of bifilm defects with a corresponding improvement in the mechanical properties. Such significant effect of the process parameters studied on the casting properties suggests that the more careful and quiescent mould filling practice and the lower the hydrogen level of the casting, the higher the quality and reliability of the castings produced.

ROS-Mediated Anti-Angiogenic Activity of Cerium Oxide Nanoparticles in Melanoma Cells.

Angiogenesis plays a key role in cancer progression, including transition to the metastatic phase via reactive oxygen species (ROS)-dependent pathways, among others. Antivascular endothelial growth factor (VEGF) antibodies have been trialed as an anti-angiogenic therapy for cancer but are associated with high cost, limited efficacy, and side effects. Cerium oxide nanoparticles (nanoceria) are promising nanomaterials for biomedical applications due to their ability to modulate intracellular ROS. Nanoceria can be produced by a range of synthesis methods, with chemical precipitation as the most widely explored. It has been reported that chemical precipitation can fine-tune primary particle size where a limited number of synthesis parameters were varied. Here, we explore the effect of temperature, precipitating agent concentration and rate of addition, stirring rate, and surfactant concentration on nanoceria primary particle size using a fractional factorial experimental design approach. We establish a robust synthesis method for faceted nanoceria with primary particle diameters of 5-6 nm. The nanoceria are not cytotoxic to a human melanoma cell line (Mel1007) at doses up to 400 μg/mL and are dose-dependently internalized by the cells. The intracellular ROS level for some cells that internalized the nanoceria is reduced, which correlates with a dose-dependent reduction in angiogenic gene expression including VEGF. These findings contribute to our knowledge of the anti-angiogenic effects of nanoceria and help to develop our understanding of potentially new anti-angiogenic agents for combination cancer therapies.

A factorial experimental design approach to obtain defect-rich black TiO2 for photocatalytic dye degradation

Black titanium dioxide was synthesized from sol-gel TiO2 by a chemical reduction method using solid-state NaBH4 for use in photocatalytic degradation of methyl orange dye under both UV and visible light irradiations. A 2 × 2 × 3 factorial experimental design with two replicates was used to assess the significance of (A) calcination temperature, (B) calcination time, and (C) molar ratio of NaBH4 to TiO2 used. Black titanium dioxide that was calcined at 500 °C for 10 h, and with a molar ratio of NaBH4 to TiO2 of 1:1 exhibited the highest removal percentage of methyl orange under both UV and visible light (82.17% and 71.92%, respectively) because it contained the largest amount of surface defects (Ti3+ sites and oxygen vacancies) as suggested by XPS evidences. The surface defects acted as an electron trap and retarded the electron-hole recombination. Furthermore, the band gap energy of black TiO2 catalyst became narrower, enabling degradation under visible light. Statistical analysis indicated that out of the three main effects Factor C had the biggest impact on the photocatalytic activity. The analysis also revealed significant interactions between the amount of NaBH4 used and either calcination time or temperature.

Parametric numerical study and optimization of mass transfer and bubble size distribution in a gas-liquid stirred tank bioreactor equipped with Rushton turbine using computational fluid dynamics

Abstract Designing and optimizing a bioreactor can be an especially challenging process. Computational modelling is an effective tool to investigate the effects of various operating parameters on bioreactor performance and identify the optimum ones. In this work, a computational fluid dynamics-population balance model (CFD-PBM) was developed to elucidate the effect of different geometrical and operating parameters on the hydrodynamics and mass transfer coefficient of a batch stirred tank bioreactor. The validated model was projected to predict the effect of different parameters including the gas flow rate, the impeller off-bottom clearance, the number of agitator blades, and rotational speed of the impeller on the velocity profiles, air volume fraction, bubble size distribution, and the local gas mass transfer coefficient (K l a) in the bioreactor. Air bubble breakup and coalescence phenomena were considered in all simulations. Factorial experimental design approach was employed to statistically investigate the impacts of the aforementioned operating and geometrical parameters on K l a and bubble size distribution in the bioreactor in order to determine the most significant parameters. This can give an essential insight into the most impactful factors when it comes to designing and scaling up a bioreactor.

Investigations on achievable surface quality in milling of Ti-35Nb-7Zr-5Ta alloy

ABSTRACT β-type Titanium (Ti) alloy possesses less Young’s Modulus (E), which is significant for manufacturing of medical implants, since it reduces stress shielding effect. In this work, surface quality analysis on Ti-35Nb-7Zr-5Ta(TNZT) alloy was carried out to reveal the osseointegration characteristics. TNZT alloy was fabricated by vacuum arc melting followed by homogenization process. Microstructure analysis with X-ray diffraction spectroscopy study revealed the formulation of body-centered cubic structure in the TNZT alloy. Further high speed milling was carried out to analyze the impact of process variables on surface quality. Parameters include axial depth of cut (ap), cutting velocity (vc), and feed/tooth (fz) are taken into consideration. In general, implants are miniature in size; hence, Carbide flat end mill cutter size of 2 mm is used for investigation. 27 slots are generated under mist cooling condition by using factorial experimental design approach. Surface characteristics and morphology of machined region were examined to discover biocompatibility. It is observed that ‘ap’ and ‘vc’ significantly affect surface quality and lowest Ra of 0.422 µm was observed. It is well within the allowable value between 1 and 1.5 µm for better osseointegration. It is also revealed that microparticle deposition and groove formation intensifies when ‘ap’ is higher at 200 µm.

Design-Based Learning Framework for Introducing Factorial Experimental Design and Lab-on-a-Chip Separations in an Instrumental Chemistry Laboratory

Lab-on-a-chip devices are a critical and emerging chemical technology. New pedagogical tactics that effectively capture both analytical chemistry concepts along with the design elements unique to these devices are necessary for effective integration in the undergraduate chemistry curriculum. This article develops a design-based learning laboratory exercise to concurrently introduce analytical miniaturization, chemical separations, and formal factorial design of experiment methods in an Introduction to Instrumental Analysis course. A new student-accessible lab-on-a-chip fabrication platform using a benchtop laser cutter allows for rapid, iterative, and safe production of student-designed microchip capillary electrophoresis devices in minutes. Student teams used a full factorial experimental design approach to efficiently screen three experimental variables of their choice when evaluating the separation speed of their own lab-on-a-chip devices. This laboratory exercise has been successfully implemented on three occasions over the past several years at Colorado College. Both reflective and performance-based assessment methods suggest this exercise is an effective pedagogical approach for realizing the intended learning outcomes.

On the use of laser-scanning vibrometry for mechanical performance evaluation of 3D printed specimens

In this study, we explored the suitability of laser-scanning vibrometry (LSV) for evaluation of the mechanical behavior of rectangular prisms produced by Fused Filament Fabrication (FFF). Our hypothesis was that LSV would be able to discriminate the mechanical behavior of specimens fabricated with different process parameters combinations. Build orientation, raster angle, nozzle temperature, printing speed and layer thickness were the process parameters of interest. Based on a factorial design of experiment approach, 48 different process parameter combinations were taken into account and 96 polylactic acid (PLA) rectangular prisms were fabricated. The characterization of their dynamical behavior provided frequency data, making possible the computation of an equivalent elastic modulus metric. Statistical analysis of the equivalent elastic modulus dataset confirmed the significant influences of raster angle, build orientation and nozzle temperature. Moreover, multivariate regression models served to rank, not only the significant influences of individual process parameters, but also the significant quadratic and cubic interactions between them. The previous knowledge was then applied to generate an ad hoc model selecting the most important factors (linear and interactions). The predicted equivalent elastic moduli provided by our ad hoc model were used in modal analysis simulations of both 3D printed rectangular prisms and a complex part. The simulated frequencies thus obtained were generally closer to the experimental ones (≤11%), as compared to modal analysis simulations based on internal geometry modelling (≤33%). The use of LSV appears very promising in the characterization of the mechanical behavior and integrity of 3D printed parts. Other additive manufacturing technologies may benefit from the use of this technique and from the adoption of the presented methodology to test, simulate and optimize the properties of 3D printed products.

Experimental estimation and numerical optimization of \u2018cylindricity\u2019 error in flow forming of H30 aluminium alloy tubes

The present article analyses the influence of flow forming input parameters on the development of “cylindricity error” in H30 aluminum alloy seamless tubes fabricated by a single pass reverse flow forming process. Measurement and control of geometrical precision in terms of cylindricity encompassing straightness and roundness are critical for the success of component manufacturing by flow forming. The experimental trials with a predefined range of input parameters conforming to the full factorial design of experiments approach have been performed, and corresponding cylindricity data have been recorded as the outcome. An empirical relation has been established between the input parameters and the cylindricity. It has been established that cylindricity value increases sharply with an increase in axial stagger contributing 39% to the outcome, whereas the percentage contributions of in-feed and feed-speed ratio are found to be less than 1%. The adequacy of the proposed model has further been analyzed and validated through the confirmation tests. In order to obtain better control over the overall process towards achieving higher productivity and accuracy, 2 meta-heuristic optimization algorithms namely, teaching and learning-based algorithm and genetic algorithm have been utilized for optimization of input process parameters to minimize cylindricity error. Both the algorithms predict that a combination of higher feed rate and lower value of axial stagger and in-feed parameters is essential to achieve the lowest cylindricity error in H30 Al alloy. Confirmatory experimental trials have been carried out to validate both the regression model and optimization, and have been found to agree well with the model predictions described herein.

Ultrasonic-assisted drilling of nickel-based super alloy in conel 601: An experimental study

In this study, a comparison between ultrasonic-assisted drilling (UAD) and conventional drilling (CD) is presented under different feed rates using thrust force, torque, and hole geometrical errors as output responses. The experiments were done on plates of Inconel 601 (nickel-based superalloy), which is classified as a difficult-to-cut alloy due to its high Nickel content (60%), high hardness (43 HRC), and low thermal conductivity. The experiments were performed using DMG Mori Ultrasonic 20 linear, which is equipped with ultrasonic tool holderoscillating at 20 kHz with 7 μm amplitude. A coated carbide single margin twist drill had been used in the experiments. Full factorial design of experiments approach was employed, and the results had been statistically analyzed to find the most significant factor affecting the process responses. The results showed that the ultrasonic assistance had reduced the thrust force, and torque compared to conventional drilling (CD). Also, a reduction in holecylindricity error was detectedduring UAD, whichimprovesthe hole quality. In case of UAD, twist drills did not suffer from a physical wear, however notch wear was observed in CD drills. Chip morphology was also studied. Short segmented chips were obtained when using UAD which improved chip evacuation and reduced the chance of chip jamming in the drill flutes.

Heat Treatment Optimization of CA-6NM Cast Alloy Using a Full Factorial Design of Experiments Approach

A full factorial experimental design was used to study the effect of each parameter involved in the heat treatment of the CA-6NM cast alloy, in order to optimize this process for achieving specific hardness values after single or double tempering-processes. The statistical analysis of the experimental results with ANOVA showed that the chemical composition, the equivalent Cre/Nie ratio and the carbon content are critical parameters that should be considered for the determination of AC1 temperature. For a single tempering process, a decrement from 30HRC to 25HRC was reached as the austenitizing and tempering temperatures were increased or with prolonged austenitizing times. In order to achieve specific hardness values < 23HRC with a double tempering-process, it is necessary to increase the first tempering temperature, increase time in the first and second tempering and use a more severe cooling rate between both tempering stages. Procedures for hardness level optimization in this alloy with both tempering processes were proposed using contour plots, which were obtained from a mathematical model that had been statistically validated.

Vertical versus shared e-leadership approach in online project-based learning: a comparison of self-regulated learning skills, motivation and group collaboration processes

The purpose of this research is to examine the effect of vertical and shared e-leadership approaches on self-regulated learning skills, motivation and group collaboration processes (group cohesion, group atmosphere, and group transactive memory system) in online project-based learning. The study was carried out according to a factorial experimental design (2 × 2) and mixed methods approach was used. The study was conducted on 41 teacher candidates randomly assigned to vertical and shared e-leadership groups. As a data collection tool; Self-Regulated Learning Scale, Motivation Scale, Transactive Memory Scale, Group Atmosphere Scale, Group Cohesion Scale, and a semi-structured interview form were used. Research findings indicate that there is no statistically significant difference between vertical and shared e-leadership groups in terms of self-regulated learning skills, motivation and group collaboration processes. In other words, both leadership approaches were found to be useful in the management of groups in online project-based learning. The qualitative findings of the research reveal that there are some advantages and disadvantages in both approaches. In this context, the shared e-leadership approach is determined to be useful especially in terms of fostering the sense of belonging to the group by sharing the leadership role within the group, ensuring a fair distribution of responsibility and workload among the group members. The vertical e-leadership approach was found to be useful in providing communication, cooperation and coordination among the group members thanks to the group leader, ensuring the planned progress of the group works.

A New Mechanism in Determining the Number of Geothermal Wells for Power Plant Development Using Stochastic Method

The number of geothermal wells (production, injection, make-up) should be calculated carefully to get the optimum values for the technical aspect of power plant development. However, the method for calculating the number of wells has been used is a deterministic approach that involves only a single value for every parameter. Since the result of this method is a single value, it cannot capture the uncertainties of the field parameters. Therefore, this paper proposed the newest method that applied 2-level full factorial design of experiment approach with the help from Minitab software to cover the uncertainties of the field parameters and to produce the probabilistic number of wells in combination with Monte Carlo Simulation. The proposed method has been successfully used to calculate the number of wells in the case study of Karaha-Talaga Bodas field. Based on the study, the most significant factors for determining the number of production and injection wells are the fluid enthalpy and total mass flow rate, whereas for the make-up wells number are the decline rate and make-up well capacity. 5 production wells, 1 injection well, and 4 make-up wells are the minimum requirement number of wells that should be drilled for generating 30 MW power plant capacity in 30 years.

Optimizing the alignment of thermoresponsive poly(N-isopropyl acrylamide) electrospun nanofibers for tissue engineering applications: A factorial design of experiments approach.

Thermoresponsive polymers, such as poly(N-isopropyl acrylamide) (PNIPAM), have been identified and used as cell culture substrates, taking advantage of the polymer’s lower critical solution temperature (LCST) to mechanically harvest cells. This technology bypasses the use of biochemical enzymes that cleave important cell-cell and cell-matrix interactions. In this study, the process of electrospinning is used to fabricate and characterize aligned PNIPAM nanofiber scaffolds that are biocompatible and thermoresponsive. Nanofiber scaffolds produced by electrospinning possess a 3D architecture that mimics native extracellular matrix, providing physical and chemical cues to drive cell function and phenotype. We present a factorial design of experiments (DOE) approach to systematically determine the effects of different electrospinning process parameters on PNIPAM nanofiber diameter and alignment. Results show that high molecular weight PNIPAM can be successfully electrospun into both random and uniaxially aligned nanofiber mats with similar fiber diameters by simply altering the speed of the rotating mandrel collector from 10,000 to 33,000 RPM. PNIPAM nanofibers were crosslinked with OpePOSS, which was verified using FTIR. The mechanical properties of the scaffolds were characterized using dynamic mechanical analysis, revealing an order of magnitude difference in storage modulus (MPa) between cured and uncured samples. In summary, cross-linked PNIPAM nanofiber scaffolds were determined to be stable in aqueous culture, biocompatible, and thermoresponsive, enabling their use in diverse cell culture applications.

Electrochemical degradation of triclosan in aqueous solution. A study of the performance of an electro-Fenton reactor

The electro-Fenton degradation of Triclosan in aqueous solution was studied using a cylindrical reactor in which polarized carbon cloth electrodes and a cation exchange resin were employed. Using a factorial design of experiments approach, the effect of four variables (considering two levels for each one), was measured on four response parameters that reflect the electrooxidation efficiency of the electrochemical reactor. The results revealed that in all cases triclosan degradation was very efficient (above 95%) and that while there is a reasonable effect of all variables and their interactions, the one with the strongest influence on the process is the nature and magnitude of the ionic strength of the electrolytic solution. In this way, while the presence of a buffer species in this solution can keep the pH in a value that affects the generation of •OH radicals from the Fenton mixture, a high ionic strength solution can promote the elimination of Fe ionic species from the reactor by decreasing resin Fe retention due to competition effects of other ions for the binding sites of the substrate. HPLC experiments of the effluent solutions, also revealed that the degradation by-products of triclosan were dependent on the nature and ionic strength of the electrolytic solution in the electro-Fenton process under study. Finally, comparison of the different operation modes, also suggested that electro-adsorption of Fe cationic species in the negatively polarized cathode surface, is the main factor that controls Fe ion retention within the reactor.

The antifungal potential of (Z)-ligustilide and the protective effect of eugenol demonstrated by a chemometric approach

Mankind is on the verge of a postantibiotic era. New concepts are needed in our battle to attenuate infectious diseases around the world and broad spectrum plant-inspired synergistic pharmaceutical preparations should find their place in the global fight against pathogenic microorganisms. To progress towards the discovery of potent antifungal agents against human pathologies, we embarked upon developing chemometric approach coupled with statistical design to unravel the origin of the anticandidal potential of a set of 66 essential oils (EOs). EOs were analyzed by GC-MS and tested against Candida albicans and C. parapsilosis (Minimal Inhibitory Concentration, MIC). An Orthogonal Partial Least Square (OPLS) analysis allowed us to identify six molecules presumably responsible for the anticandidal activity of the oils: (Z)-ligustilide, eugenol, eugenyl acetate, citral, thymol, and β-citronellol. These compounds were combined following a full factorial experimental design approach in order to optimize the anticandidal activity and selectivity index (SI = IC50(MRC5 cells)/MIC) through reconstituted mixtures. (Z)-Ligustilide and citral were the most active compounds, while (Z)-ligustilide and eugenol were the two main factors that most contributed to the increase of the SI. These two terpenes can, therefore, be used to construct bioinspired synergistic anticandidal mixtures.

Development of sustainable acid blue 113 dye adsorption system using nutraceutical industrial Tribulus terrestris spent

First-ever study was done using a low-cost Tribulus terrestris spent, a by-product of a nutraceutical industry as an effective biosorbent for removing acid blue 113 (AB113) from aqueous media. The effect of various factors such as pH, dye concentration, amount of adsorbent, particle size of adsorbent, contact time as also temperature on adsorption have been studied. Analysis of equilibrium data was done by using two number of two-parameter and six number of three-parameter isotherm models. Kinetic studies on adsorption were done using models like pseudo-first order and pseudo-second order. Webber–Morris and Dumwald–Wagner diffusion models helped to study diffusion. Determination and evaluation were also done for change in enthalpy (ΔH°), entropy (ΔS°), and Gibbs free energy (ΔG°) of adsorption system. Scanning electron microscopy, Fourier transform infrared spectroscopy and determination of point of zero-charge were carried out for surface characterization of the adsorbent. We have used a two-level fractional factorial experimental design approach and subsequently analysis of variance to define a statistically developed model from which we obtained values of above parameters which yielded maximum possible adsorption as 93.00 mg/g. The investigations proved that nutraceutical industrial T. terrestris spent is both cost-effective and an efficient biosorbent for the remediation of AB113 dye from aqueous system and textile industrial effluent.