Atomic Scale Responses of High Entropy Oxides to Redox Environments.

The potential of high entropy oxides (HEOs) as high-performance energy storage materials and catalysts has been mainly understood through their bulk structures. However, the importance of their surfaces, which may play an even more critical role, remains largely unknown. In this study, we employed advanced scanning transmission electron microscopy to investigate the atomic-scale structural and chemical responses of CeYLaHfTiZrOx HEOs to high-temperature redox environments. Our observations reveal dynamic elemental and structural reconstructions in the surface of HEOs under different gas environments, contrasting with the high stability of the bulk structure. Notably, the surfaces of HEO particles consistently exhibit abundant oxygen vacancies, regardless of the redox environment. These findings indicate that HEOs offer distinct advantages in facilitating chemical and electrochemical reactions, relying on oxygen vacancies. Our results also suggest that the exceptional performance of HEOs in energy storage applications arises from surface structural and chemical adaptability.

Effective remediation of mercury (II) from aqueous solutions using CS-MnFe2O4-CoS-MWCNTs: Box-Behnken design optimization and adsorption isotherm, kinetics, and thermodynamics evaluation.

Mercury (Hg) is a hazardous heavy metal, non-biodegradable and toxic, posing a serious threat to aquatic life and human health. Therefore, the removal of Hg ions from contaminated water using effective and eco-friendly adsorbents is necessary. In the present study, three magnetic chitosan-based organic-inorganic nanocomposites, such as CS-MnFe2O4, CS-MnFe2O4-CoS, and CS-MnFe2O4-CoS-MWCNTs, were designed and constructed to investigate their capacity for adsorbing Hg ions from aqueous solutions. The physicochemical properties of prepared composites were characterized by various analyses. The BET analyses indicated their high surface area and porous structure, and the N2 adsorption-desorption showed that the modification of CS in three stages by MnFe2O4 and crosslinking reaction, CoS preparation, and MWCNT incorporation resulted in increased N2 adsorption. The XRD confirms the synthesis of MnFe2O4 and CoS in the CS matrix and also the distinct peaks of MWCNTs. The CS-MnFe2O4-CoS-MWCNTs showed acceptable thermal stability with 45% char yields and superparamagnetic properties with magnetic saturation (Ms) of 16 emu g-1. The interactive impacts of independent variables (pH, contact time, and adsorbent dosage) on the removal percentage of Hg(II) onto three prepared adsorbents, as well as the process optimization, were assessed by the Box-Behnken design. The optimum conditions were identified, and the data from the analysis of variance showed that the three independent factors (pH, contact time, and adsorbent dosage) significantly influenced the adsorption of Hg(II). The adsorption isotherm and thermodynamics analysis investigation showed that at low concentrations of Hg(II), the adsorption process was both endothermic and spontaneous for the studied adsorbents.

Inoculum-to-substrate ratio and solid content effects over in natura spent coffee grounds anaerobic digestion.

Coffee is the second most traded commodity worldwide, and its production is associated with the generation of a large number of residues, which are underused and disposed of in landfills. Notably, the coffee industry annually generates approximately 6 million tons of industrial spent coffee ground (ISCG) when extracting coffee flavorings to produce soluble coffee. That resource loss scenario has been highlighted in sustainable waste management contexts as an opportunity to improve the coffee circular economy. Despite ISCG bioconversion to methane potentially meets the waste-to-energy purposes of reducing residues disposal in landfills, decreasing greenhouse gas (GHG) emissions, and increasing renewable energy sources, data about anaerobic digestion (AD) of ISCG remains quite restricted. That limitation becomes more apparent owing to the lack of data focusing on AD key parameters for ISCG as substrate. This study assessed the influence of inoculum-to-substrate ratio (ISR) and the solid content influences on mesophilic (37 °C) ISCG-AD throughout the Response Surface Methodology (RSM) and Central Composite Design (CCD). Results revealed that both factors, ISR and solid content, should be kept above a certain threshold of 0.5 and 6.0 gTVS L-1 to ensure experimental reliability, as well as reproductively and above 1.0 and 8.0 gTVS L-1 to avoid underestimation on the MY potential achieved. Concerning ISCG-AD kinetics, the quadratic model optimum condition was at 1.36 and 14.83 gTVS L-1 for ISR and solid content, respectively. This optimum range for ISR and solid content could guide further development of process configurations for mono- and co-digestion of ISCG, avoiding underestimation of the MY potential and extended incubation periods.

HSPiP and QbD Program-Based Analytical Method Development and Validation to Quantify Ketoconazole in Dermatokinetic Study.

Ketoconazole (KTZ) is the most potential azole anti-mycotic drug. The quantification of KTZ from various layers of the skin after topical application of lipidic nanocarriers is critical. We addressed a sensitive, specific, simple, rapid, reproducible, and economic analytical method to quantify KTZ from the treated skin homogenate using the Hansen solubility parameter (HSP, HSPiP software)-based modeling and experimental design. The software provided various HSP values for KTZ and solvents to compose the mobile phase. The Taguchi model identified the significant sets of factors to develop a robust bioanalytical method with reduced variability. In the optimization, acetonitrile (ACN) concentration (X1 as A) and the pH of mobile phase (X2 as B) were two factors against two responses (Y1: peak area and Y2: retention time). The HPLC (high-performance liquid chromatography) method validation was carried out based on US-FDA guidelines for the developed KTZ formulations (suspension, solid nanoparticles, and commercial product) extracted from the treated rat skin. The experimental solubility of KTZ was found to be maximum in the two solvents (ACN and ethyl acetate), based on HSP values. Surface response methodology (SRM) identified remarkable impact of ACN concentration and the mobile phase pH on the peak area and retention time. Analytical limits (0.17 and 0.50 µg/mL) were established for KTZ-SLNs (extracted from the skin). The method was implemented with high reproducibility, accuracy, and selectivity to quantify KTZ from the treated rat skin.

Mycotoxins in food: a review on liquid chromatographic methods coupled to mass spectrometry and their experimental designs.

The development of a multi-mycotoxins method using LC-MS/MS is necessary and it is clear that the development of such method involves many compromises in the choice of the different parameters. This review summarizes applications using conventional experimental designs and some recent studies using response surface methodology (RSM) as a mathematical modeling tool for the optimization of extraction procedures. The authors also discuss pros and cons of the different procedures. To our knowledge, it is the first review on experimental design for the development of multi-mycotoxin methods. This review could be useful in the development and optimization of LC-MS/MS methods with the aim of describing experimental design and variables (factors) that are likely to affect sensitivity and specificity.

Evaluation of Plant-Based Byproducts as Green Fining Agents for Precision Winemaking.

Consumers are increasingly looking for foods, including wine, that are free of animal-derived proteins. This study seeks to evaluate patatin, a new, plant-based and allergen-free fining agent, by comparing it with the fining agents polyvinipolypyrrolidone, bovine serum albumin, and methylcellulose. Specifically, its effects on the phenolic profile of enological tannins were analyzed with four spectrophotometric assays: OD 280 nm, Folin−Ciocâlteu, Adams−Harbertson, and methylcellulose. In addition, changes in the polyphenol composition of Sangiovese red wine were determined by UV-Vis spectrophotometry and HPLC with adsorption trials, and the solid−liquid interaction in a wine solution was modeled by both Langmuir and Freundlich equations. Our findings highlight the occurrence of systematic proportional error between the selected spectrophotometric assays. As a result, direct comparisons of protein precipitation assays can be made only among results obtained with the same spectrophotometric method. However, it is clear that patatin has an impact on the phenolic profile of Sangiovese red wine: it removes simple phenolics (gallic acid, (+)-catechin, (−)-epicatechin, epicatechin gallate, syringic acid, fertaric acid, coutaric acid, and rutin) as well as both oligomeric and polymeric tannins to different extents. In concentrations of less than 1 g/L, the patatin isotherm showed a linear relation between the equilibrium concentration and the quantity absorbed, obeying the Freundlich model reasonably well (KF 1.46; 1/n 1.07; R2 0.996 with 1/n > 1). Thus, the adsorption process is strongly dependent on the fining dosage.

Optimization of the Physical, Optical and Mechanical Properties of Composite Edible Films of Gelatin, Whey Protein and Chitosan.

The aim of this work was to evaluate the effect of the concentration of gelatin (G) (3-6 g), whey protein (W) (2.5-7.5 g) and chitosan (C) (0.5-2.5 g) on the physical, optical and mechanical properties of composite edible films (CEFs) using the response surface methodology (RSM), as well as optimizing the formulation for the packaging of foods. The results of the study were evaluated via first- and second-order multiple regression analysis to obtain the determination coefficient values with a good fit (R ˃ 0.90) for each of the response variables, except for the values of solubility and b*. The individual linear effect of the independent variables (the concentrations of gelatin, whey protein and chitosan) significantly affected (p ≤ 0.05) the water vapor permeability (WVP), strength and solubility of the edible films. The WVP of the edible films varied from 0.90 to 1.62 × 10-11 g.m/Pa.s.m2, the resistance to traction varied from 0.47 MPa to 3.03 MPa and the solubility varied from 51.06% to 87%. The optimized values indicated that the CEF prepared with a quantity of 4 g, 5 g and 3 g of gelatin, whey protein and chitosan, respectively, provided the CEF with a smooth, continuous and transparent surface, with L values that resulted in a light-yellow hue, a lower WVP, a maximum strength (resistance to traction) and a lower solubility. The results revealed that the optimized formulation of the CEF of G-W-C allowed a good validation of the prediction model and could be applied, in an effective manner, to the food packaging industry, which could help in mitigating the environmental issues associated with synthetic packaging materials.

Do Flavonoids from Durum Wheat Contribute to Its Bioactive Properties? A Prospective Study.

A clear gap with respect to the potential biological properties of wheat flavonoids exists in the available literature. This information is crucial for breeding programs aiming to produce new varieties presenting improved health benefits. Accordingly, advanced breeding lines of whole durum wheat were evaluated in this contribution. The highest recovery of phenolics was achieved using aqueous acetone (50:50, v/v), as verified by multi-response optimization, thus showing that phenolics could be largely underestimated by employing an inappropriate extraction. The concentration of derivatives of apigenin, the main phenolics present, ranged from 63.5 to 80.7%, as evaluated by LC-ESI-QTOF-MS. Phenolics from the breeding line 98 exhibited the highest ability in scavenging peroxyl radicals, reducing power as well as in terms of inhibition of pancreatic lipase activity, a key enzyme regulating the absorption of triacylglycerols. In contrast, none of the samples exhibited a significant anti-diabetic potential. Despite their high concentration compared to that of phenolic acids, results of this work do not support a significant antioxidant and pancreatic lipase inhibitory effect of durum wheat flavonoids. Therefore, breeding programs and animal and/or human trials related to the effect of durum wheat flavonoids on oxidative stress and absorption of triacylglycerols are discouraged at this point.

Microwave-Assisted Extraction of Curcuma longa L. Oil: Optimization, Chemical Structure and Composition, Antioxidant Activity and Comparison with Conventional Soxhlet Extraction.

Curcuma root (Curcuma longa L.) is a very important plant in gastronomy and medicine for its unique antiseptic, anti-inflammatory, antimicrobial and antioxidant properties. Conventional methods for the extraction of curcuma oil require long extraction times and high temperatures that can degrade the active substances. Therefore, the objectives of the present study were: (i) first, to optimize the extraction yield of curcuma oil by applying a Box-Behnken experimental design using surface response methodology to the microwave-assisted extraction (MAE) technique (the independent variables studied were reaction time (10-30 min), microwave power (150-200 W) and curcuma powder/ethanol ratio (1:5-1:20; w/v); and, (ii) second, to assess the total phenolic content (TPC) and their antioxidant activity of the oil (at the optimum conditions point) and compare with the conventional Soxhlet technique. The optimum conditions for the MAE were found to be 29.99 min, 160 W and 1:20 w/v to obtain an optimum yield of 10.32%. Interestingly, the oil extracted by microwave-assisted extraction showed higher TPC and better antioxidant properties than the oil extracted with conventional Soxhlet technique. Thus, it was demonstrated that the method applied for extraction influences the final properties of the extracted Curcuma longa L. oil.

Synthesis and characterization of hydrochar from industrial Capsicum annuum seeds and its application for the adsorptive removal of methylene blue from water.

Chili seeds (CS) represent one of the most abundant residues in Mexico due to the high production and consumption. In this work, CS were used as raw material for the production of low-cost adsorbents for the removal of methylene blue from water. The adsorbents were synthesized from a hydrothermal treatment (based on a surface response experiment design) and characterized texturally by assessing changes in their properties. The mass yield (%R), carbon content (%C), and the second order adsorption rate constant (k2) were derived in relation to a list of input variables (e.g., the reaction temperature, residence time, and water/biomass ratio). Accordingly, those output variables were affected most sensitively by temperature and/or residence time, while changes of the water/biomass ratio were insignificant. Besides, an increase in the reaction temperature favored the degradation of the lignocellulosic material with increases in the carbon fixation. The adsorption capacity of methylene blue (MB) by the hydrochars depended drastically on the oxygen/carbon ratio. As such, the maximum adsorption capacity value of 145 mg g-1 was attained at the initial MB concentration of ~3000 µM (optimal oxygen/carbon value of 0.43). On the other hand, the maximum partition coefficient (KD) was estimated as 2.96 µM-1 mg g-1 with the initial/equilibrium concentrations of 20.5/6.93 µM. The performance evaluation between different studies, when made in terms of KD, suggests that the tested hydrochar should be one of the best adsorbents to treat methylene blue, especially at near-real environmental conditions (e.g., below micromolar levels).

Optimization of ultrasonication curcumin-hydroxylated lecithin nanoemulsions using response surface methodology.

Ultrasonication technology was used to enhance the solubility and availability of lipophilic compounds as curcumin. This study aimed to know the optimal conditions to produce ultrasonication curcumin nanoemulsions stabilized with hydroxylated lecithin using response surface methodology and to evaluate some physical characteristics. Nanoemulsions were produced according to a Central Composite Face-center Design: surfactant oil ratio (SOR, 0.33-1.17), amplitude (A, 8-92%), and ultrasonication time (t, 2-18.4 min). Dynamic light scattering was used to measure the droplet size and polydispersity index of the nanoemulsions. Our results showed that a second-order polynomial function of amplitude and ultrasonication time model fitted well with the mean droplet size and polydispersity of the emulsions. Predicted droplet size was 122.2 nm and polydispersity index was 0.13 obtained at optimal conditions: SOR = 0.72, A = 92%, and t = 12 min. The nanoemulsions remained stable during 15 days of storage at 20 °C. Nanoemulsion remained stable to the aggregation in the pH range from 7.0 to 3.0, while the droplet size increased at lower pH values due to a loss of charge of the lecithin. Nanoemulsion applied in a sugar-beverage showed a yellow-green translucent color, showing better stability on the droplet size than the beverage with the coarse emulsion. Nanoemulsion could be used as a natural colorant in beverages.

Optimization of the enzymatic hydrolysis of Moringa oleifera Lam oil using molecular docking analysis for fatty acid specificity.

Alternative strategies are required to develop the optimized production of fatty acids using biocatalysis; molecular docking and response surface methodology are efficient tools to achieve this goal. In the present study, we demonstrate a novel and robust methodology for the sustainable production of fatty acids from Moringa oleifera Lam oil using lipase-catalyzed hydrolysis (without the presence of emulsifiers or buffer solutions). Seven commercial lipases from Candida rugosa (CRL), Burkholderia cepacia (BCL), Thermomyces lanuginosus (TLL), Rhizopus niveus (RNL), Pseudomonas fluorescens (PFL), Mucor javanicus (MJL), and porcine pancreas (PPL) were used as biocatalysts. Initial screening showed that CRL had the highest hydrolytic activity (hydrolysis degree of 81%). Molecular docking analysis contributed to the experimental results, showing that CRL displays more stable binding free energy with oleic acid (C18:1), which is the fatty acid of highest concentration in Moringa oleifera Lam oil. To evaluate and optimize the hydrolysis process, response surface methodology (RSM) was used. The effect of temperature, mass ratio oil:water, and hydrolytic activity on enzymatic hydrolysis was evaluated by central composite design using RSM. Under the optimized conditions (temperature of 37 °C, mass ratio oil:water of 25%, and hydrolytic activity of 550 U goil -1 ), the maximum hydrolysis degree (100%) was achieved. The present study provides a robust method for the enzymatic hydrolysis of different oils for efficient and sustainable fatty acid production.

Combined effects of oregano essential oil and salt on the growth of Escherichia coli in salad dressing.

There is a broad research interest in the search for alternatives to chemical additives for use as natural food preservatives. Although many natural compounds have biological in vitro properties evidenced, in situ studies are still scarce. This study evaluated the effect of oregano essential oil (OEO) and salt (NaCl) concentrations against Escherichia coli (ATCC 8739), in salad dressing, using the response surface methodology. The experiment included a 22 central composite rotatable design (CCRD) in a total of 11 formulations of salad dressings. Oregano essential oil was characterized by gas chromatography and salad dressings by ash, lipids, proteins and moisture. OEO was composed mainly by carvacrol (65.1%) and p-cymene (12.0%). Salad dressings showed similar chemical profiles. A mathematical model for the prediction of the antibacterial activity in salad dressing was obtained. The results revealed that the interaction between OEO and salt showed effect on the bacterial count. However, the effect of salt was negative suggesting that the highest NaCl concentrations decreases the bacterial count. Therefore, within the parameters studied, the use of OEO to control E. coli in salad dressing can be considered promising and allows reduction in the levels of salt to be incorporated in food.

Influence of culture conditions towards optimal carotenoid production by Gordonia alkanivorans strain 1B.

With the increasing awareness on the toxicity of several synthetic dyes, demand for pigments from natural sources, such as microbial carotenoids, has gained interest as a promising safe alternative colour additive. In this study, a surface response methodology based on the Doehlert distribution for two factors [% of glucose in a mixture of glucose + fructose (10 g/L total sugars), and sulfate concentration] was used towards the optimal carotenoids production by Gordonia alkanivorans strain 1B in the presence of light (400 lx). Time influence on pigment production by this bacterium was also evaluated, as well as the cell viability profile during longer incubation periods at optimal conditions. Indeed, the highest carotenoid production (2596-3100 µg/gDCW) was obtained when strain 1B was cultivated in the optimal conditions: glucose 10 g/L and sulfate ≥ 22 mg/L, in the presence of light for 19 days at 30 °C, 150 rpm. Flow cytometry showed that the highest production was somehow related with the cellular stress. These results highlight the great potential of strain 1B as a new hyperpigment producer to be exploited towards several applications.

Synthesis and characterization of polysulfone/graphene oxide nano-composite membranes for removal of bisphenol A from water.

Bisphenol A (BPA) is an emerging contaminant of water resources that disrupts endocrine function. Attempts are continuing to develop cost-effective methods to remove BPA from water environments. The aim of this study was to prepare and characterize polysulfone/graphene oxide nano-composite membranes for removal of BPA from water. Three membranes were synthetized using phase inversion method: polysulfone membrane as PSF and two polysulfone/graphene oxide nano-composite membranes with graphene oxide (GO) weight ratios of 0.4 and 1.0% as PSF/GO 0.4% and PSF/GO 1.0%, respectively. The membrane characteristics including morphology, surface roughness, pore size, zeta potential and presence of functional groups were determined using field emission scanning electron microscopy, atomic force microscopy, streaming potential, and attenuated total reflectance Fourier transform infrared spectroscopy techniques. Inclusion of GO remarkably increased permeate flux of the membranes, so that pure water flux of PSF, PSF/GO 0.4% and PSF/GO 1.0% at operating pressure of 2 bar was determined 226, 449 and 512 L/m2 h, respectively. The membrane PSF/GO 0.4% with the most negative zeta potential (-10.46 mV) and the highest BPA removal efficiency was determined as the optimal membrane. The optimum conditions of input pressure, operating time, initial concentration of BPA, and pH for BPA removal efficiency by PSF/GO 0.4% were determined using surface response methodology to be 1.02 bar, 10.6 min, 7.5 mg/L, and 5.5, respectively. By optimizing the conditions of operating parameters, experimental BPA removal efficiency by PSF/GO 0.4% reached to as high as 93%.

Increase of content and bioactivity of total phenolic compounds from spent coffee grounds through solid state fermentation by Bacillus clausii.

Spent coffee grounds are waste material generated during coffee beverage preparation. This by-product disposal causes a negative environmental impact, in addition to the loss of a rich source of nutrients and bioactive compounds. A rotating central composition design was used to determine the optimal conditions for the bioactivity of phenolic compounds obtained after the solid state fermentation of spent coffee grounds by Bacillus clausii. To achieve this, temperature and fermentation time were varied according to the experimental design and the total phenolic and flavonoid content, antioxidant activity and antimicrobial activity were determined. Surface response methodology showed that optimum bioprocessing conditions were a temperature of 37 °C and a fermentation time of 39 h. Under these conditions, total phenolic and flavonoid contents increased by 36 and 13%, respectively, in fermented extracts as compared to non-fermented. In addition, the antioxidant activity was increased by 15% and higher antimicrobial activity was observed against Gram positive and negative bacteria. These data demonstrated that bioprocessing optimization of spent coffee grounds using the surface response methodology was an important tool to improve phenolic extraction, which could be used as an antioxidant and antimicrobial agents incorporated into different types of food products.

Optimization of Spray Drying Conditions for Yield, Particle Size and Biological Activity of Thermally Stable Viral Vectors.

PURPOSE: This work examines the relevance of viral activity in the optimization of spray drying process parameters for the development of thermally stable vaccine powders. In some instances, the actual active pharmaceutical ingredient (API) is not included in the process optimization as it is deemed too costly to use until the final selection of operating conditions, however, that approach is inappropriate for highly labile biopharmaceutics. We investigate the effects of spray drying parameters on i) yield, ii) particle size and iii) viral vector activity of a mannitol/dextran encapsulated recombinant human type 5 adenoviral vector vaccine, to demonstrate the effects and magnitude of each effect on the three responses, and further show that the API must be included earlier in the optimization. METHODS: A design of experiments approach was used with response surface methodology (RSM) to optimize parameters including inlet temperature, spray gas flow rate, liquid feed rate and solute concentration in the feed. RESULTS: In general, good conditions for maintaining viral activity led to reduced yield and fewer particles of the desired size. Within the range of parameters tested, the yield varied from 50 to 90%, the percentage of ideally size particles was 10-50%, and the viral vector titre loss was 0.25-4.0 log loss. CONCLUSIONS: RSM indicates that the most significant spray drying parameters are the inlet temperature and spray gas flow rate. It was not possible to optimize all three output variables with one set of parameters, indicating that there will only be one dominant criteria for processing which in the case of viral vaccines will likely be viral vector activity.

Optimized extraction of a single-chain variable fragment of antibody by using aqueous micellar two-phase systems.

In this work, the purification of a single-chain variable fragment (scFv) of an antibody by using liquid-liquid extraction in aqueous micellar two-phase systems was optimized by means of central composite design. Protein partitioning assays were performed by using the selected system composition in previous works: Triton X-114 at 4% wt/wt, yeast fermentation supernatant at 60% wt/wt, McIlvaine buffer pH 7.00. The other system component concentrations, Cibacron Blue F3GA (CB), Fabsorbent™ F1P HF (HF) and NaCl, were selected as independent variables. ScFv recovery percentage (%R) and purification factor (PF) were selected as the responses. According to the optimization process both, scFv recovery percentage and purification factor were favored with the addition of HF and NaCl in a range of concentrations around the central point of the second central composite design (HF 0.0120% w/w, CB 0.0200% w/w, NaCl 0.200% w/w). These experimental conditions allowed the concentration and pre-purification of scFv in the micelle-rich bottom phase of the systems with a recovery percentage superior to 88% and a purification factor of approximately 3.5. These results improved the previously presented works and demonstrated the convenience of using aqueous micellar two-phase systems as a first step in the purification of scFv molecules.

Post-treatment of molasses wastewater by electrocoagulation and process optimization through response surface analysis.

Molasses wastewater is a high strength effluent of food industry such as distilleries, sugar and yeast production plants etc. It is characterized by a dark brown color and exhibits a high content in substances of recalcitrant nature such as melanoidins. In this study, electrocoagulation (EC) was studied as a post treatment step for biologically treated molasses wastewater with high nitrogen content obtained from a baker's yeast industry. Iron and copper electrodes were used in various forms; the influence and interaction of current density, molasses wastewater dilution, and reaction time, on COD, color, ammonium and nitrate removal rates and operating cost were studied and optimized through Box Behnken's response surface analysis. Reaction time varied from 0.5 to 4 h, current density varied from 5 to 40 mA/cm(2) and dilution from 0 to 90% (v/v expressed as water concentration). pH, conductivity and temperature measurements were also carried out during each experiment. From preliminary experiments, it was concluded that the application of aeration and sample dilution, considerably influenced the kinetics of the process. The obtained results showed that COD removal varied between 10 and 54%, corresponding to an operation cost ranging from 0.2 to 33 euro/kg COD removed. Significant removal rates were obtained for nitrogen as nitrate and ammonium (i.e. 70% ammonium removal). A linear relation of COD and ammonium to the design parameters was observed, while operation cost and nitrate removal responded in a curvilinear function. A low ratio of electrode surface to treated volume was used, associated to a low investment cost; in addition, iron wastes could be utilized as low cost electrodes i.e. iron fillings from lathes, aiming to a low operation cost due to electrodes replacement. In general, electrocoagulation proved to be an effective and low cost process for biologically treated molasses-wastewater treatment for additional removal of COD and nitrogen content and color reduction. Treated effluent samples with good quality were produced by EC, with COD, NH4-N and NO3-N concentrations of 180, 52 and 2 mg/l respectively. Response surface analysis revealed that optimized conditions could be established under moderate molasses wastewater dilution, (e.g. 45%), at 3.5 h treatment time and 33 mA/cm(2) current density.

Isolation, characterization and response surface method optimization of cellulose from hybridized agricultural wastes.

This study explores the utilization of eight readily available agricultural waste varieties in Nigeria-sugarcane bagasse, corn husk, corn cob, wheat husk, melina, acacia, mahogany, and ironwood sawdust-as potential sources of cellulose. Gravimetric analysis was employed to assess the cellulose content of these wastes, following which two selected wastes were combined based on their cellulose content and abundance to serve as the raw material for the extraction process. Response Surface Methodology, including Box-Behnken design, was applied to enhance control over variables, establish an optimal starting point, and determine the most favorable reaction conditions. The cellulose extracted under various conditions was comprehensively examined for content, structure, extent of crystallinity, and morphological properties. Characterization techniques such as X-ray Diffraction, Scanning Electron Microscopy, and Fourier Transform Infrared Spectroscopy were employed for detailed analysis. Compositional analysis revealed sugarcane bagasse and corn cob to possess the highest cellulose content, at 41 ± 0.41% and 40 ± 0.32% respectively, with FTIR analysis confirming relatively low C=C bond intensity in these samples. RSM optimization indicated a potential 46% isolated yield from a hybrid composition of sugarcane bagasse and corn cob at NaOH concentration of 2%, temperature of 45 °C, and 10 ml of 38% H2O2. However, FTIR analyses revealed the persistence of non-cellulosic materials in this sample. Further analysis demonstrated that cellulose isolated at NaOH concentration of 10%, temperature of 70 °C, and 20 ml of 38% H2O2 was of high purity, with a yield of 42%. Numerical optimization within this extraction condition range predicted a yield of 45.6% at NaOH concentration of 5%, temperature of 45 °C, and 20 ml of 38% H2O2. Model validation confirmed an actual yield of 43.9% at this condition, aligning closely with the predicted value. These findings underscore the significant potential of combinning and utilizing agricultural wastes as a valuable source of cellulose, paving the way for sustainable and resource-efficient practices in various industrial applications.