Central Composite Design Methodology Research Articles

Optimized production of a truncated form of the recombinant neuraminidase of influenza virus in Escherichia coli as host with suitable functional activity

BackgroundTo discover effective drugs for treating Influenza (a disease with high annual mortality), large amounts of recombinant neuraminidase (NA) with suitable catalytic activity are needed. However, the functional activity of the full-length form of this enzyme in the bacterial host (as producing cells with a low cost) in a soluble form is limited. Thus, in the present study, a truncated form of the neuraminidase (derived from California H1N1 influenza strain) was designed, then biosynthesized in Escherichia coli BL21 (DE3), Shuffle T7, and SILEX systems. E. coli BL21 (DE3) was selected as a best host for statistical optimization. Using central composite design methodology, neuraminidase expression level was measured at 20 different runs considering most effective factors including; concentration of isopropyl-β-D-thiogalactopyranoside (IPTG), temperature, and induction time.ResultThe recombinant neuraminidase was purified using Ni-affinity chromatography in soluble form. The neuraminidase expression was confirmed by western blot technique with a molecular mass of 48 kDa. The optimum expression condition was at temperature (30°C), induction time (3 h), and concentration of IPTG (0.6 mM) resulting in maximum neuraminidase expression (7.6 µg/mL) with P < 0.05. The analysis of variance with the significant value of R2 (0.97) indicated that the quadratic model utilized for this prediction was highly significant (p < 0.0001). Applying the optimized condition led to a ~ 2.2-fold increase in NA expression level (from 3.4 to 7.6 µg/ml). The kinetic parameters were also confirmed by fluorescent signals (by 2’-(4-Methylumbelliferyl)-α-D-N acetyl neuraminic acid substrate) with specific activity; ~3.5 IU/mg and Km: 86.49 ± 0.1 µ, close to the Vibrio Cholera neuraminidase with specific activity; 4 IU/mg. The neuraminidase inhibition test confirmed the inhibition of the neuraminidase activity by the drug inhibitor (Oseltamivir) compared to the control sample.ConclusionThe high quality and proper functional activity of the truncated neuraminidase described in this research show that E. coli can be a suitable host for a wide range of applications with less cost and risk compared to eukaryotic expression systems.

Adsorptive processes applied to the defluorination of groundwater for human consumption

Contamination of groundwater by fluoride ions can occur through both natural and anthropogenic activities, such as the discharge of industrial waste containing this compound. Thus, effective fluoride removal from groundwater is essential to ensure safe drinking water. This study evaluated the performance of adsorption techniques for defluoridating groundwater in Rio Grande do Sul, Brazil. Preliminary tests were conducted using synthetic solutions with a fluoride concentration of 5 mg.L−1, applying several adsorbents. Additionally, an ultrasonic process was used to synthesize an adsorbent from activated alumina pre-treated with carbon (AACP) and modified with ZnCl₂ (AA-ZnCl₂). The AACP and AA-ZnCl2 were characterized through BET, EDS, scanning electron microscopy, X-ray diffraction (XRD), and FT-IR analysis. A Central Composite Design and response surface methodology were applied to optimize adsorption efficiency, focusing these factors: pH and adsorbent dosage. Kinetic and isotherm adsorption tests were conducted for both AACP and AA-ZnCl₂. The results showed that AACP achieved fluoride removal efficiencies of 65.4 % in synthetic solutions and 38.6 % in groundwater. The AA-ZnCl₂ demonstrated superior performance, removing over 98 % of fluoride in synthetic solutions and 55.4 % in groundwater, across a pH range of 4 to 10, with an optimal solid dosage of 3 g.L−1. For an initial fluoride concentration of 5 mg.L−1, a removal efficiency of 97.4 % was achieved within 5 min of contact time. The kinetic adsorption data were best described by the pseudo-second-order model, while the Freundlich isotherm model provided the best fit for the adsorption isotherm data. The findings in this work indicate hat ZnCl₂-modified activated alumina, synthesized with ultrasonic assistance, is highly effective for defluoridating groundwater for safe human consumption being an alternative method to be implemented in an industrial scale.

Development of a Dual-Stage CIM® CDI Reactor with Immobilized Glucuronan Lyases and Laccases for Sustainable Synthesis of Antioxidant Phenolized Oligoglucuronan

Immobilized enzyme reactors (IMERs) are critical tools for developing novel oligosaccharides based on the enzymatic catalysis of polysaccharides. In this paper, a novel glucuronan lyase from Peteryoungia rosettiformans was produced, purified, and then immobilized on a CIM® CDI disk for cleaving glucuronan. The results showed that around 63.6% of glycuronan lyases (800.9 μg) were immobilized on the disk. The Vmax values of immobilized glucuronan lyases did not significantly change (56.9 ± 4.7 μM∙min−1), while the Km values (0.310 ± 0.075 g∙L−1) increased by 2.5 times. It is worth noting that immobilized glucuronan lyases overcame the catalytic inhibition of free enzymes observed under high glucuronan concentrations (0.5–2 g∙L−1). circumscribed central composite design (CCCD) and response surface methodology (RSM) showed that glucuronan concentration, flow rate, and reaction time significantly affected the yield of oligoglucuronans. The degree of polymerization (DP) of degraded glucuronan ranged from DP 2–8 according to the results obtained by high performance anion exchange chromatography coupled with a pulsed amperometric detector (HPAEC-PAD). The IMER retained 50.9% activity after running 2373 column volumes of glucuronan. Finally, this glucuronan lyase reactor was tentatively connected to an immobilized laccase reactor to depolymerize, and gallic acid (GA) was added to glucuronan. Approximately 8.5 mg of GA was added onto 1 g of initial glucuronan, and the GA–oligoglucuronan conjugates showed notable antioxidant activity.

Determine the Balance of Nitrogen, Potassium, and Silicon Fertilization for the Control of Rice Tungro Disease Using Response Surface Methodology

This study evaluates the efficacy of combined N, K, and Si treatments to find the balance of these three elements for tungro disease control and rice grain production. The study was conducted in a pot under a glasshouse. These elements were chosen as several findings have indicated the positive benefits of nitrogen (N), potassium (K), and silicon (Si) fertilization on plant development, yield, and biotic stress relief. The methods used were central composite design and response surface methodology. Complete and balanced nutrition has always been the first line of defense for plants due to the direct involvement of mineral elements in plant protection. The results showed that rice tungro disease could be controlled with 138:42:62:200 (N:P2O5:K2O:Si). A high rate of nitrogen is needed to reduce disease development. The results on N may explain that not all conditions of rice plants are at risk with high N rates. Adding Si fertilizer contributes to plant defense mechanisms and plays a role in yield formation. In contrast, the balance of fertilizer for maximizing grain yield per plant was found to be not dependent on nitrogen but needed either low K (62 kg K2O/ha) or high K (80 kg K2O/ha) but with moderate Si (150 kg Si/ha). Prioritizing tungro disease control and adopting the rate of N:K2O:Si (138:62:200), it was found that there was a yield reduction of an average of 7.7%.

Applying liquisolid technique to enhance curcumin solubility: a central composite design study

Turmeric, specifically its curcuminoids such as curcumin (C21H20O6), possesses extensive therapeutic benefits including anti-inflammatory, anticancer, and anti-aging properties. However, curcumin’s clinical effectiveness is significantly limited by its hydrophobic nature, leading to poor bioavailability. This study aims to enhance the solubility and bioavailability of curcumin through the development of liquisolid compact dispersion formulations. To address curcumin’s limited water solubility (3.12 mg/l at 25 °C) and high oil–water partition coefficient (logKow=3.29\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{log}Kow=3.29$$\\end{document}), we employed a central composite design (CCD) to optimize liquisolid compact dispersion formulations. The optimization focused on the tablet’s physical properties, such as hardness, disintegration time, and dissolution rate at 30 min. Critical formulation components included Tween 80 as the liquid vehicle and Aerosil 200 as the coating material, serving as independent variables in the optimization process. The optimized formulation, containing 30 mg of Tween 80 and 75 mg of Aerosil 200, significantly improved curcumin’s dissolution rate. Experimental results confirmed the formulation’s effectiveness, with a marked reduction in the time to dissolve 63.2% of the drug to 165 min, compared to 300 min for conventional formulations. Differential scanning calorimetry and Fourier-transform infrared spectra indicated a transformation of curcumin into a non-crystalline state and the formation of hydrogen bonds with Tween 80, contributing to enhanced solubility. This study successfully demonstrates a viable strategy to enhance the bioavailability of curcumin through liquisolid compact dispersion formulations. By addressing the solubility challenges of curcumin, this technique presents a significant advancement in improving the clinical applicability of BCS class II and IV drugs, potentially benefiting a wide range of therapeutic applications.Graphical abstractGraphical representation of optimizing curcumin liquisolid formulationusing central composite design (CCD) methodology

Experimental Study on Optimizing Hydrogen Production from Sludge by Microwave Catalytic Pyrolysis Using Response Surface Methodology.

Catalytic pyrolysis technology is a harmless and useful solid waste treatment method. Studying the catalytic pyrolysis of sludge for hydrogen production is of practical significance. Therefore, this paper prepared a bifunctional catalyst with both microwave absorption and catalytic properties from electroplating sludge through carbonization and acid modification processes and then was characterized by XRD, BET, SEM, XPS, and FTIR. An experimental study employed a conventional-then-microwave pyrolysis method to investigate the catalytic pyrolysis process of municipal sludge. Combining central composite design (CCD) and response surface methodology (RSM) with three factors and five levels, this paper investigated the interactive effects of the conventional pyrolysis temperature, microwave irradiation time, and catalyst addition ratio on the unit hydrogen production (UHP) of sludge. A predictive model based on a second-order polynomial regression equation was developed. The results revealed that the catalyst possesses a specific surface area and pore structure and that the second-order polynomial model fits well. The conventional pyrolysis temperature, microwave irradiation time, catalyst addition ratio, and interaction between the latter two significantly affected the UHP of sludge. The optimal operation conditions of conventional pyrolysis temperature, microwave irradiation time, and catalyst addition ratio were 462.7 °C, 8.8 min, and 12.4%, respectively. Under these optimal conditions, the UHP was 13.22 mmol/g, with a relative error of only 1.12% compared to the predicted model value of 13.37 mmol/g.

Rubber seed shell as low-cost medium to produce lactic acid using Lactobacillus plantarum LB2 and fabrication of a polylactic acid-chitosan composite for fish fillet packing

Rubber seed shell (Hevea brasiliensis) was used as a low-cost substrate to produce lactic acid via Lactobacillus plantarum LB2. The medium components were initially screened by two-level full factorial design. Three variables (pH, moisture, and polyoxyethylene sorbitan monooleate (PSM)) were used in the central composite design and response surface methodology. The amount of PSM was found to be a significant variable in lactic acid production. Lactic acid was purified and used for the chemical fabrication of a polylactic acid-chitosan composite film. Compared with the polylactic acid, the composite film improved the tensile strength, elongation strength, and tearing strength. The film prepared with 1% chitosan-polylactic acid exhibited the maximum antibacterial activity against Bacillus cereus (21 ± 1 mm) and the lowest activity against Escherichia coli (10 ± 1 mm). The polylactic acid-chitosan film prepared with 1% chitosan was used as a packing material to store the fish fillets and presented reduced mesophilic (4.3 ± 0.1 Log CFU/g) and psychrotropic (3.2 ± 0.2 Log CFU/g) bacterial populations compared with those of the control (4.9 ± 0.2 Log CFU/g and 3.7 Log CFU/g). Rubber seed shells can be used as an alternative culture medium for lactic acid production, to reduce the production cost of polylactic acid.

Optimization of shrimp and crab shell as bio-flocculant for Chlorella pyrenoidosa harvesting using response surface methodology

The use of bio-flocculants in flocculation processes offers a feasible approach for separating solid and liquid phases, with a particular focus on microalgae harvesting. Critical parameters such as the dose of bio-flocculant, pH level, and dose of cationic inducer significantly impact the success of microalgae harvesting. This study aims to examine the efficacy of chitosan derived from shrimp shells and crab shells as bio-flocculants in microalgae harvesting, specifically Chlorella pyrenoidosa. Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed in this study to attain optimal flocculation conditions, characterized by high flocculation efficiency and short settling time. The optimal harvesting condition using chitosan derived from shrimp shells was achieved at 0.499 g/L of bio-flocculant, pH 9.09, and 0.172 g/L of cationic inducer with 92.58% efficiency and 133.49 s settling time. Meanwhile, The optimal harvesting condition with chitosan derived from crab shells was achieved at 0.434 g/L of bio-flocculant, pH 8.96, and 0.168 g/L of cationic inducer. This resulted in an efficiency of 93.72% and a settling time of 117 s. Based on this fact, the potential of shrimp shells and crab shells as bio-flocculants for Chlorella pyrenoidosa harvesting is evident. Furthermore, the efficacy of flocculation and settling time are significantly influenced by variables such as the concentration of cationic inducers, the levels of bio-flocculants, and pH.

Corrosion Rate Optimization and Prediction for Enhanced Strength and Structural Integrity of Pipeline Weldments Using RSM and ANN

This study investigates the optimization and prediction of non-elastic performance factors required to augment the pipeline weldments' structural integrity and strength. The study's main focus is on the components of the operation, like the welding current, voltage, and gas flow rate to optimize and predict the corrosion rate of the pipeline weldment. Utilizing Design Expert software for experimental design and data analysis, the study employs the Central Composite Design (CCD) methodology to generate a quadratic model that predicts the responses effectively. The research also integrates Artificial Neural Networks (ANN) to further enhance the prediction accuracy. Experimental results indicate that the optimal welding parameters 160 amps current, 21.28 volts voltage, and 14.67 liters/min gas flow rate—yield a corrosion rate of 0.018 mm/yr. The study concludes that both RSM and ANN can be effectively used for optimization and prediction in welding processes, with RSM showing slightly better predictive capabilities.

Fluoro-Hydroxyapatite/Chitosan composites as an eco-friendly adsorbent for Direct Red 23 dye removal: Optimization through Response Surface Methodology

This study presents the development of an innovative and eco-friendly Fluoro-Hydroxyapatite/Chitosan (FHAP-CS) adsorbent for removing Direct Red 23 (DR23) dye from aqueous solutions. Synthesized via the sol-gel method by incorporating fluoride (F) and chitosan (CS) into hydroxyapatite, FHAP-CS was characterized using FTIR, XRD, SEM, TGA, and N2 adsorption/desorption to evaluate its structural, surface, and morphological properties. The results demonstrated that FHAP-CS exhibited enhanced particle definition, reduced particle size, increased surface area, and superior adsorption capacity compared to pure HAP, HAP-CS, and FHAP.The adsorption of DR23 dye onto FHAP-CS was optimized using Central Composite Design and Response Surface Methodology. The results demonstrated that the quadratic regression models were statistically significant (R² = 0.99) and can accurately predict adsorption behavior. The monolayer adsorption mechanism of DR23 dye onto FHAP-CS was confirmed by fitting the batch adsorption data to the Langmuir isotherm model, and the process followed pseudo-second-order kinetic models. Under optimal conditions: a [DR23]0= 350 mg/L, pH of 5.11, FHAP-CS dose of 1.60 g/L, agitation speed of 240 rpm, and contact time of 120 min the adsorption capacity reached approximately 152.36 mg g-1. These findings suggest that FHAP-CS is an effective and cost-efficient adsorbent for removing hazardous azo dyes from wastewater.

Investigating the Impact of Process Parameters on Bead Geometry in Laser Wire-Feed Metal Additive Manufacturing

Laser wire-feed metal additive manufacturing (LWAM) is an innovative technology that shows many advantages compared with traditional manufacturing approaches. Despite these advantages, its industrial adoption is limited by complex parameter management and inconsistent process quality. To address these issues and improve geometric accuracy, this study explores how process parameters influence bead geometry. We conducted a parameter study varying laser power, wire feed rate, traverse speed, and welding angle. Using a full factorial design with a central composite design methodology, we assessed bead height and width. This allowed us to develop a model to estimate ideal process parameters. The findings offer a detailed analysis of parameter interactions and their effects on bead geometry, aiming to enhance geometric accuracy and process stability in LWAM. Moreover, we have evaluated the proposed process parameters from our developed model, which showed a significant enhancement to the overall quality. This was validated via printing a single layer and multi-layer structures. The quality of the final predicted sample using the proposed method was improved by 40% compared to the best sample produced for the Design of Experiment trials.

Polystyrene nanoplastics: optimized removal using magnetic nano-adsorbent and toxicity assessment in zebrafish embryos.

The presence of microplastics (MPs) and nanoplastics (NPs) in aquatic ecosystems has raised serious environmental and health concerns. Polystyrene is one of the most abundant plastic polymers found in the environment. Polystyrene MPs/NPs have harmful implications for human health and their removal from the environment has become a serious challenge. In this study, we investigated the adsorptive uptake of polystyrene nanoplastics (PS NPs) from aqueous solutions using fly ash-loaded magnetic nanoparticles (FAMNPs) as the magnetic nano-adsorbent. During the factor screening study, the adsorption process was studied as a function of four variables namely pH (5-10), adsorption time (30-120min), amount of FAMNPs (0.01-0.04g), and stirring speed (50-200rpm). Central composite design (CCD) and response surface methodology (RSM) were employed to establish the relationship between the variables. Furthermore, toxicity assessments of PS NPs were checked on a zebrafish model, shedding light on its potential ecological effects. Two variables namely the pH and amount of FAMNPs significantly influenced the adsorption capacity of FAMNPs and were further optimized for subsequent analysis. The optimum operational readings proposed by the model were pH (8.5), and the amount of FAMNPs (0.03g), resulting in a good adsorption capacity of 29.12mg/g for PS NPs. The adequacy of the proposed model was evaluated by analysis of variance (ANOVA). Zebrafish embryos exposed to PS NPs revealed physical deformations such as pericardial edema and malformed notochord. The study demonstrates the effectiveness of FAMNPs in the adsorption of PS NPs from aqueous solutions, with optimal conditions identified at pH 8.5 and 0.03g of FAMNPs using RSM. The adequacy of the model was confirmed through ANOVA analysis. Toxicity assessments on zebrafish embryos exposed to PS NPs revealed significant mortality and physical deformations, highlighting the importance of PS NPs removal for environmental health.

Synthesis and characterization of etherified cationic starch flocculant derived from Manihot esculenta peel with varying degrees of substitution

Cationic Manihot esculenta (ME) peel starch was synthesized through etherification method using 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC) as cationizing monomer. The optimization of the main factors influencing the degree of substitution (DS) was conducted using central composite design (CCD) and response surface methodology (RSM). The factors assessed include CHPTAC concentration, catalyst sodium hydroxide (NaOH) concentration, and reaction time. The DS values of the cationic starches were obtained between 0.39 and 0.99. The maximum DS value was up to 0.99 at 0.615 mol/L of CHPTAC, 30 % (w/v) NaOH, and a reaction time of 5 h. The finding based on the optimization using RSM reflected that CHPTAC and NaOH concentrations are the key variables determining the DS value, while reaction time has a negligible impact on the etherification process. Furthermore, the chemical composition, morphology, and structure of the cationic ME peel starch were characterized by scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and nuclear magnetic resonance spectroscopy (1H NMR). It was confirmed that the modifying monomers penetrated the surface layer of the starch granules and attached to the starch backbone.

Short-chain fructooligosaccharides synthesis using a commercial enzyme complex from Aspergillus sp. and anti-cancer activity on HCT116 and HT-29 cell lines

Over the last years, short-chain fructooligosaccharides (FOS) have gained significant attention as valuable food and dietary supplement components. Apart from implications such as dietary fibres, sweeteners, and humectants, FOS are hailed for their prebiotic properties. Moreover, much research is dedicated to their role as anti-cancer agents. Despite the ongoing interest, both technical aspects, challenges of FOS production, and their anti-cancer role necessitate more in-depth investigations to understand their healthcare role better. This study aimed to optimise critical FOS synthesis parameters using a commercial enzyme, Viscozyme® L, to obtain a preparation with a high FOS content. A central composite design and response surface methodology evaluated the effect of pH, temperature, synthesis time, substrate, and enzyme load on multiple responses, chosen as independent variables, were utilised to define optimal conditions. Under the optimal conditions (temperature 50 °C, pH 5.5, sucrose concentration 352 g/L, enzyme concentration 2.5% v/v, and 5.5 h of reaction), a preparation with a total FOS content of 58.8% was obtained. The FOS preparation showed minimal in vitro antioxidant capacity in the ORAC, CUPRAC, and ABTS*+assays. In addition, the cytotoxicity of FOS against tested cell lines was evaluated. FOS did not reduce HT-29 cell viability even at the concentration of 2.5 mg/mL, whereas FOS inhibited the proliferation of HCT116 cells by 50% at 2.35 mg/mL. Finally, the sensitisation effect of FOS on HCT116 cell treatment with doxorubicin has been revealed.

Utilization of banana peel waste for the production of bioethanol and other high-value-added compounds

Bananas (Musa sp.) are one of the most produced crops worldwide, surpassing 100 million tons per year, and considering that approximately 30 % of their weight consists of peels, the annual generation of these residues is significant. Banana residues are rich in nutrients; nowadays, they are all disposed of in landfills. As a novelty, this work showed that it could be used for other things, such as alcohol, D-Limonene, and citric acid production. This study characterized the biomass, optimized pretreatment, and enzymatic hydrolysis and evaluated the fermentation process using this biomass, using the central composite design (CCD) methodology. The planning variables included sulfuric acid (H2SO4) concentration, banana peel waste mass in the pretreatment stage, and commercial cellulase enzyme (Sigma-Aldrich) concentration in the enzymatic hydrolysis stage. The responses quantified were sugars, ethanol, and acids using high-performance liquid chromatography, and the D-Limonene content was determined on a gas chromatograph coupled to a mass spectrometer. The highest yield of total reducing sugars found after enzymatic hydrolysis was 11.88 g/L, while the ethanol yield was 1.37 g/L. In the recovery of D-Limonene, the obtained value was 0.56 mg/g. The values of fermentable sugars confirm banana peel waste as a potential biomass for biorefinery processes. Furthermore, the possibility of an integrated D-Limonene recovery is essential in obtaining bioproducts. In this sense, it can be concluded that utilizing these residues is promising in reducing environmental issues and valorizing food waste.

Ni-Based Molecular Sieves Nanomaterials for Dry Methane Reforming: Role of Porous Structure and Active Sites Distribution on Hydrogen Production.

Global warming, driven by greenhouse gases like CH4 and CO2, necessitates efficient catalytic conversion to syngas. Herein, Ni containing different molecular sieve nanomaterials are investigated for dry reforming of methane (DRM). The reduced catalysts are characterized by surface area porosity, X-ray diffraction, Raman infrared spectroscopy, CO2 temperature-programmed desorption techniques, and transmission electron microscopy. The active sites over each molecular sieve remain stable under oxidizing gas CO2 during DRM. The reduced 5Ni/CBV10A catalyst, characterized by the lowest silica-alumina ratio, smallest surface area and pore volume, and narrow 8-ring connecting channels, generated the maximum number of active sites on its outer surface. In contrast, the reduced-5Ni/CBV3024E catalyst, with the highest silica-alumina ratio, more than double the surface area and pore volume, 12-ring sinusoidal porous channels, and smallest Ni crystallite, produced the highest H2 output (44%) after 300 min of operation at 700 °C, with a CH4:CO2 = 1:1, P = 1 atom, gas hour space velocity (GHSV) = 42 L gcat-1 h-1. This performance was achieved despite having 25% fewer initial active sites, suggesting that a larger fraction of these sites is stabilized within the pore channels, leading to sustained catalytic activity. Using central composite design and response surface methodology, we successfully optimized the process conditions for the 5Ni/CBV3024E catalyst. The optimized conditions yielded a desirable H2 to CO ratio of 1.00, with a H2 yield of 91.92% and a CO yield of 89.16%, indicating high efficiency in gas production. The experimental results closely aligned with the predicted values, demonstrating the effectiveness of the optimization approach.

Synergizing metakaolin and waste-glass for sustainable and functional UHPCC– a central composite design and ecological footprint assessment

Optimizing ultra-high-performance cementitious composites (UHPCC) with sustainable materials often compromises certain properties due to the chemical nature of alternative binders used to replace standard UHPCC components like Portland cement (OPC) and microsilica (MS). In the context of Waste-Glass-UHPCC, the reduction in early strength, attributed to the varied pozzolanic reactivity of MS and recycled glass powder as cementitious materials, may reduce its application that requires high early strength. This study addresses the early strength deficiency of Waste-Glass-UHPCC by incorporating metakaolin (MK) and also aims to assess the impact of MK on 28-day compressive strength, durability, and carbon footprint. Research investigating the effects of MK on UHPCC with reduced OPC and MS content is currently limited. Specifically, this investigation explores the influence of MK on UHPCC characterized by a cement content of 620 kg/m3. By utilizing advanced statistical methods [i.e., the Central Composite Design (CCD) and Response Surface Methodology (RSM)], this study investigates the substitution of MK for OPC in formulations of Waste-Glass-UHPCC. The experimental design comprises 18 encoded mixtures, allowing for the development of second-order regression models for critical responses [slump flow and compressive strength at different ages]. Besides, visualization through RSM-3D graphs facilitates a comprehensive examination of the effects of various factors. For a deeper analysis, two of the CCD's points, i.e., SP-12 (Waste-Glass-UHPCC without metakaolin), and SP-10 (Waste-Glass-UHPCC with 65.77 kg of metakaolin per cubic meter) were further investigated along with a control dosage that represents a typical UHPCC formulation. The responses studied encompassed 1, 7, and 28 d compressive strength, chloride ion penetration, and carbon footprint measured by a systematic life cycle analysis (following ISO 15804), assessing the environmental impact of the UHPCC's making materials from raw extraction to disposal. Despite encountering challenges in meeting self-compacting concrete criteria due to MK's tendency to accelerate hydration, the enhanced early strength properties (61 % higher than those of the Waste-Glass-UHPCC) make the MK-based mixture appropriate for various applications such as bridge engineering or pavement rehabilitation. Additionally, the addition of MK in UHPCC formulation demonstrated superior resistance to chloride ion permeability even compared to the control mixture, attributed to MK's ability to enhance the concrete's microstructure and capture chloride ions, attributed to Friedel's salt formation. Noteworthy findings include a significant (27 %) reduction in carbon footprint with the incorporation of MK in Waste-Glass-UHPCC compared to the control counterparts. The current study highlights the durability and environmental advantages of MK-based UHPCC blends while emphasizing the critical requirements of workability and strength development of sustainable UHPCC.

Enhancing Microalgal Biomass and Chemical Composition for Sustainable Wastewater Treatment

The research explores enhancing microalgal biomass production and its chemical composition for sustainable wastewater treatment. By using the Central Composite Design (CCD) methodology, nutrient concentrations and microbial components in the growth medium were optimized. Adjustments to light exposure, particularly with red and blue frequencies, significantly improved biomass yield, carbon sequestration, and protein content. Optimal light intensity further enhanced these parameters. A process incorporating on-demand CO2 supply and controlled pH levels showed potential for increasing biomass concentrations and nutrient utilization efficiency. Results demonstrated a 28% increase in biomass fixation and a 27% increase in biomass production compared to unoptimized conditions. The study emphasizes the effectiveness of integrated approaches in boosting biomass production and optimizing wastewater treatment, offering promising avenues for sustainable bio-based solutions

Harnessing Fermented Soymilk Production by a Newly Isolated Pediococcus acidilactici F3 to Enhance Antioxidant Level with High Antimicrobial Activity against Food-Borne Pathogens during Co-Culture.

In this study, a newly isolated Pediococcus acidilactici F3 was used as probiotic starter for producing fermented soymilk to enhance antioxidant properties with high antimicrobial activity against food-borne pathogens. The objectives of this study were to investigate optimized fermentation parameters of soymilk for enhancing antioxidant property by P. acidilactici F3 and to assess the dynamic antimicrobial activity of the fermented soymilk during co-culturing against candidate food-borne pathogens. Based on central composite design (CCD) methodology, the maximum predicted percentage of antioxidant activity was 78.9% DPPH inhibition. After model validation by a 2D contour plot, more suitable optimum parameters were adjusted to be 2% (v/v) inoculum and 2.5 g/L glucose incubated at 30 °C for 18 h. These parameters could provide the comparable maximum percentage of antioxidant activity at 74.5 ± 1.2% DPPH inhibition, which was up to a 23% increase compared to that of non-fermented soymilk. During 20 days of storage at 4 °C, antioxidant activities and viable cells of the fermented soymilk were stable while phenolic and organic contents were slightly increased. Interestingly, the fermented soymilk completely inhibited food-borne pathogens, Salmonella Typhimurium ATCC 13311, and Escherichia coli ATCC 25922 during the co-culture incubation. Results showed that the soymilk fermented by P. acidilactici F3 may be one of the alternative functional foods enriched in probiotics, and the antioxidation and antimicrobial activities may retain nutritional values and provide health benefits to consumers with high confidence.

Optimizing Glyphosate Removal from Water Using a Peracetic Acid-Assisted Advanced Oxidation Process: A Response Surface Methodology Approach

Glyphosate (GLY), one of the most used pesticides in the world, has been frequently detected in water, posing chronic and remote hazards to human health and the environment. Consequently, it has become necessary to develop efficient and sustainable treatment processes able to remove GLY from the polluted aquatic environments. In this context, the use of advanced oxidation processes is of great interest, as it allows for a significant reduction in concentrations of recalcitrant pollutants. In this study, peracetic acid (PAA) was used for the first time to remove GLY from water. In particular, the process parameters (oxidant dose, activation by UV radiation, GLY concentration, process time) were optimized using central composite design (CCD) and response surface methodology (RSM). The degradation of the pollutant, i.e., GLY, was monitored by ion chromatography, optimizing the instrumental parameters. During the process, residual oxidant concentrations were also constantly monitored using reference methods (i.e., UV-visible spectroscopy). Based on the results obtained, the best GLY removals (over 90%) were achieved under the following conditions: a PAA/GLY molar ratio of 3 (concentration of 3.0 mg/L for GLY and 4.0 mg/L for PAA), UV irradiation, and a process time of 45 min. The possibility of achieving total glyphosate removal by using small amounts of oxidant increases the environmental sustainability of the proposed aquatic pollution mitigation strategy.