Cu- and S- @SnO2 nanoparticles loaded on activated carbon for efficient ultrasound assisted dispersive µSPE-spectrophotometric detection of quercetin in Nasturtium officinale extract and fruit juice samples: CCD-RSM design

Study on oxidation behavior during process of recycling carbon fibers from CFRP by pyrolysis

The study utilized a pyrolysis method to recycle carbon fibers from carbon fiber reinforced polymer (CFRP), followed by oxidation to remove pyrolysis carbon. The obtained recycled carbon fibers had good mechanical properties, and the tensile strength could reach 96.2% of the virgin carbon fibers under the optimal process conditions. The recycled carbon fibers displayed similar chemical structure and graphitization degree as the virgin carbon fibers, and showed better wettability with epoxy resin. In addition, density functional theory (DFT) calculations were also employed to analyze the mechanism of pyrolysis carbon oxidation removal. The results showed that the adsorption energy of oxygen on pyrolytic carbon and the reaction activation energy were lower than those of carbon fibers, indicating that pyrolytic carbon was more easily oxidized than carbon fibers. This allowed pyrolytic carbon to be removed by oxidation at relatively low temperatures and preserved the integrity of carbon fibers, thus ensuring that the carbon fibers also maintained excellent mechanical properties after recycling. This study helps to reveal the oxidation mechanism of resin pyrolysis carbon, providing technical support for efficient and clean recycling of carbon fibers.

Analytical Methods for the Determination of Quercetin and Quercetin Glycosides in Pharmaceuticals and Biological Samples

Flavonoids are plant-derived compounds that have several health benefits, including antioxidative, anti-inflammatory, anti-mutagenic, and anti-carcinogenic effects. Quercetin is a flavonoid that is widely present in various fruits, vegetables, and drinks. Accurate determination of quercetin in different samples is of great importance for its potential health benefits. This review, is an overview of sample preparation and determination methods for quercetin in diverse matrices. Previous research on sample preparation and determination methods for quercetin are summarized, highlighting the advantages and disadvantages of each method and providing insights into recent developments in quercetin sample treatment. Various analytical techniques are discussed including spectroscopic, chromatographic, electrophoretic, and electrochemical methods for the determination of quercetin and its derivatives in different samples. UV-Vis (Ultraviolet-visible) spectrophotometry is simple and inexpensive but lacks selectivity. Chromatographic techniques (HPLC, GC) offer selectivity and sensitivity, while electrophoretic and electrochemical methods provide high resolution and low detection limits, respectively. The aim of this review is to comprehensively explore the determination methods for quercetin and quercetin glycosides in diverse matrices, with emphasis on pharmaceutical and biological samples. The review also provides a theoretical basis for method development and application for the analysis of quercetin and quercetin glycosides in real samples.

A new approach to prediction riboflavin absorbance using imprinted polymer and ensemble machine learning algorithms

The molecularly imprinted polymer (MIP) is useful for measuring the amount of riboflavin (vitamin B2), in various samples using UV/Vis instruments. The practical optimization of the MIP synthesis conditions has a number of drawbacks, like the need to spend money, the need to spend time, the use of the compounds that cause contamination, needing laboratory equipment and tools. Using machine learning (ML) to predict the amount of riboflavin absorbance is a creative solution to overcome the problems and shortcomings of optimizing polymer synthesis conditions. In fact, by using the model without needing real work in the laboratory, the optimum laboratory conditions are determined, and as a result the maximized absorption of the riboflavin is obtained. In this paper, MIP was synthesized for selective extraction of the riboflavin, and UV/Vis spectrophotometry was used to quantitatively measure riboflavin absorbance. Various factors affect the performance of the polymer. The effect of six important factors, including the molar ratio of the template, the molar ratio of monomer, the molar ratio of cross-linker, loading time, stirring rate, and pH, were investigated. Then, using ensemble ML algorithms, like gradient boosting (GB), extra trees (ET), random forest (RF), and Ada boost (Ada) algorithms, an accurate model was created to predict the riboflavin absorption. Also, the mutual information feature selection method was used to determine the important features. The results of using feature selection method was shown that variables such as the molar ratio of the template, the molar ratio of the monomer, and the molar ratio of the cross-linker had a high effect on riboflavin absorbance. The GB and Ada boost algorithms performed better than ET and RF algorithms. After tuning the n-estimator hyper parameter (n-estimator = 300), the GB algorithm was shown an excellent performance in predicting the absorbance of riboflavin and the maximum R²-scoring of the model was obtained at 0.965995, the minimum of the mean absolute error (MAE), and mean square error (MSE) of the model respectively were obtained -0.003711 and -0.000078. Therefore, by using the proposed model, it is possible to predict riboflavin absorbance theoretically, and with high accuracy by changing the inputs of model, and using the model instead of working in the lab saves time, money, chemical compounds, and lab ware.

Sustainable extraction of ligustilide and ferulic acid from Angelicae Sinensis Radix, for antioxidant and anti-inflammatory activities

The 2030 Agenda for Sustainable Development envisions a rational use of energy and resources in all technological processes. However, in the extraction methods of compounds from medicinal plants and herbs, there is an urgent to reduce the use of organic solvents and increase the energy efficiency of these methods. Therefore, a sustainable extraction method (enzyme and ultrasonic co-assisted aqueous two-phase extraction, EUA-ATPE) of simultaneous extraction and separation of ferulic acid and ligustilide from Angelicae Sinensis Radix (ASR) was developed by integrating enzyme-assisted extraction (EAE) with ultrasonic-assisted aqueous two-phase extraction (UAE- ATPE). The effects of different enzymes, extraction temperature, pH, ultrasonic time, liquid-to-materials ratio, etc., were optimized by single-factor experiments and central composite design (CCD). Under the optimum conditions, the highest comprehensive evaluation value (CEV) and extraction yield were obtained by EUA-ATPE. Furthermore, recovery (R), partition coefficient (K), and scanning electron microscopy (SEM) analysis revealed that enzyme and ultrasonic treatment improved mass transfer diffusion and increased the degree of cell disruption. Besides, the EUA-ATPE extracts have shown great antioxidant and anti-inflammatory activity in vitro. Finally, compared to different extraction methods, EUA-ATPE achieved higher extraction efficiency and higher energy efficiency due to the synergistic effect between EAE and UAE-ATPE. Therefore, the EUA-ATPE provides a sustainable method for extracting bioactive compounds from medicinal plants and herbs, contributing to Sustainable Development Goals (SDG), including SDG-6, SDG-7, SDG-9, SDG-12, and SDG-15.

Synthesis of highly porous three-dimensional PVA/GO/ZIF-67 cryogel for the simultaneous treatment of waters contaminated with cadmium (II) and lead (II) heavy metal ions

In this research, PVA/GO/ZIF-67 cryogel as a highly porous three-dimensional polymeric adsorbent was synthesized by freeze-drying method and applied for the simultaneous removal of Cd2+ and Pb2+ ions from contaminated...

Fluorescent carbon dots from Indian Bael patra as effective sensing tool to detect perilous food colorant

Herein a simple strategy has been demonstrated for the synthesis of environmentally amiable and highly fluorescent carbon dots from the most useful plant of Indian classical Ayurveda i.e. Bael patra fruit. The morphological features and chemical composition of the prepared carbon dots were characterized through High resolution transmission electron microscopy, Field emission scanning electron microscopy and X-ray photoelectron spectroscopy. Owing to their highly emission nature, the applicability of carbon dots was tested against various food colorant i.e. Allura red. Under the optimized conditions, the decreased fluorescence intensity exhibited a good linear relationship with increasing concentration of Allura red. Additionally, an extensive research was carried out to determine the adsorption efficiency of carbon dots for Allura red and heavy metals. Based on the context, here we report the novelty of this work, demonstrating the decontamination of various samples from Allura red and heavy metals with the application of carbon dots.

Highly effective pre-concentration of thymol and carvacrol using nano-sized magnetic molecularly imprinted polymer based on experimental design optimization and their trace determination in summer savoury, Origanum majorana and Origanum vulgare extracts

To ascertain thymol and carvacrol in pharmaceutical syrups, a valid and effective magnetic molecular imprinted polymer dispersive solid phase microextraction (MMIP-DSPME) process was developed in this study, which was in combination with a high performance liquid chromatography-ultra violet (HPLC-UV) technique for the assessment of thymol and carvacrol separation and pre-concentration. Contact time, eluent kind and volume, pH, the mass of the MMIP were all taken into consideration as key factors. Design expert and multi-objective response surface methodology (RSM) were used to optimize these variables. The mass of the MMIP, sample pH, eluent kind, time of sorption, the volume of eluent, and time of elution were 10 mg, 6, acetonitrile, 28 min, 200 µL, and 5.5 min, respectively, for the maximum extraction recovery of the analytes. The limit of detection (LOD) was 0.042 ng mL^-1 at the optimal conditions, while the value for the limit of quantification (LOQ) was 0.140 ng mL^-1. At the optimized conditions for thymol and carvacrol, the suggested MMIP sorbent had sorption capacities of 64.1 and 72.6 mg g^-1, respectively. Furthermore, for triplicate measurements, the linear dynamic range (LDR) was 0.40-5000 ng mL^-1, and the method's accuracy (RSD %) was 6.26%. The saturation magnetization for the MMIP was 19.0 emu g^-1 obtained by VSM, allowing the sorbent to be separated quickly. The sorption experiments confirmed the large sorption capacity of the MMIP for thymol and carvacrol, as well as its homogeneous binding sites. The extraction recovery for thymol and carvacrol was 96.9-103.8% and 96.6-105.4%, respectively, at all spiked amounts (20, 100, 200, and 500 ng mL^-1). The findings of seven desorption-regeneration cycles using MMIP demonstrated the high stability of the sorbent. The MMIP revealed a particular behavior of sorption for thymol and carvacrol, implying a selective, simple, effective, and flexible analytical method.

Increased Malbranchea pulchella β-glucosidase production and its application in agroindustrial residue hydrolysis: A research based on experimental designs

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β-Glucosidases are a limiting factor for the biomass saccharification.

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β-Glucosidase was produced from thermophilic fungus Malbranchea pulchella.

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Enzyme production was optimized using composite central designs and response surface.

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Optimal production was obtained with 0.6 % cellobiose plus 4.0 % sugarcane bagasse (SCB).

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Application of Mixture Design with SCB, soybean hull and barley bagasse were tested.

β-Glucosidases are a limiting factor in the conversion of cellulose to glucose for the subsequent ethanol production. Here, β-glucosidase production by Malbranchea pulchella was optimized using Composite Central Designs and Response Surface Methodologies from a medium designed. The coefficient of determination (R²) was 0.9960, F-value was very high, and the lack of fit was found to be non-significant. This indicates a statistic valid and predictive result. M. pulchella enzymatic extract was successfully tested as an enzymatic cocktail in a mixture design using sugarcane bagasse, soybean hull and barley bagasse. We proved that the optimization of the β-glucosidase production and the application in hydrolysis using unexpansive biomass and agricultural wastes can be accomplished by means of statistical methodologies. The strategy presented here can be useful for the improvement of enzyme production and the hydrolysis process, arising as an alternative for bioeconomy.

Application of ultrasound in combination with other technologies in food processing: A review

The use of non-thermal processing technologies has been on the surge due to ever increasing demand for highest quality convenient foods containing the natural taste & flavor and being free of chemical additives and preservatives. Among the various non-thermal processing methods, ultrasound technology has proven to be very valuable. Ultrasound processing, being used alone or in combination with other processing methods, yields significant positive results on the quality of foods, thus has been considered efficacious. Food processes performed under the action of ultrasound are believed to be affected in part by cavitation phenomenon and mass transfer enhancement. It is considered to be an emerging and promising technology and has been applied efficiently in food processing industry for several processes such as freezing, filtration, drying, separation, emulsion, sterilization, and extraction. Various researches have opined that ultrasound leads to an increase in the performance of the process and improves the quality factors of the food. The present paper will discuss the mechanical, chemical and biochemical effects produced by the propagation of high intensity ultrasonic waves through the medium. This review outlines the current knowledge about application of ultrasound in food technology including processing, preservation and extraction. In addition, the several advantages of ultrasound processing, which when combined with other different technologies (such as microwave, supercritical CO2, high pressure processing, enzymatic extraction, etc.) are being examined. These include an array of effects such as effective mixing, retention of food characteristics, faster energy and mass transfer, reduced thermal and concentration gradients, effective extraction, increased production, and efficient alternative to conventional techniques. Furthermore, the paper presents the necessary theoretical background and details of the technology, technique, and safety precautions about ultrasound.

Voltammetric measurement of entacapone in the presence of other medicines against Parkinson's disease by a screen-printed electrode modified with sulfur-tin oxide nanoparticles

A screen-printed electrode (SPE) is described modified with sulfur-tin oxide nanoparticles (S@SnO₂NP) for the determination of entacapone (ENT) in the presence of other medicines against Parkinson's disease (PD). The S@SnO₂NP was synthesized through the hydrothermal method and used in the modification of the SPE. The smart utilization of the S@SnO₂NP and the SPE provided excellent properties such as high surface area and current density amplification by embedding an efficient sensing interface for highly selective electrochemical measurement. Under optimized experimental conditions, the anodic peak current related to the ENT oxidation onto the sensor surface at 0.46 V presented a linear response towards different ENT concentration sin the range 100 nM to 75 μM. The limit of detection (LOD) and electrochemical sensitivity were estimated to be 0.010 μM and 2.27 μA·μM^-1·cm^-2, respectively. The applicability of the sensor was evaluated during ENT determination in the presence of other conventional medicines againts, including levodopa (LD), carbidopa (CD), and pramipexole (PPX). The results of the analysis of human urine and pharmaceutical formulation as real samples using the developed sensor were in good agreement withre sults of high-performance liquid chromatography (HPLC) as a standard method. These findings demonstrated that the strategy based on the SPE is a cost-effective platform creating a promising candidate for practical determination of ENT in routine clinical testing.Graphical abstract.

Production, purification, and process optimization of intracellular pigment from novel psychrotolerant Paenibacillus sp. BPW19

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Pigment producing Paenibacillus sp. BPW19 was identified by phylogenetic analysis.

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Optimization of culture conditions for maximum biomass production.

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Psychrotolerant property of Paenibacillus sp. BPW19 was evaluated.

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Erucic acid occurred as major component in the extracted intracellular pigment.

A pink pigment-producing bacterial strain was isolated from wastewater and identified as Paenibacillus sp. BPW19. The motile bacterial strain was Gram-positive, acid fermenting, glucose, sucrose utilizing and rod-shaped with an average cell length of 1.55 μm as studied under the Environmental Scanning Electron Microscope. Even though being psychrotolerant, the cell growth condition of BPW19 was optimized as 25 ºC along with pH 8, and 2.25% inoculum concentration considering the operational ease of the production. Sonication assisted solvent extraction produced 5.41% crude pigment which showed zones of exclusion against gram-negative strains Escherichia coli DH5α, Enterobacter sp. EtK3, and Klebsiella sp. SHC1. Gas Chromatography-Mass Spectrometry analysis of the crude pigment exhibited the dominant presence of major compounds as dotriacontane; 3,7 dimethyl 7 octanal; 1-eicosene and erucic acid. While column chromatography (ethanol:chloroform in 1:4 (v/v) ratio) purified pigment was identified as erucic acid using Nuclear Magnetic Resonance with a net yield of 3.06%.

Selective determination of closantel by artificial neural network-genetic algorithm optimized molecularly imprinted polypyrrole using UV-visible spectrophotometry

A molecularly imprinted polymer (MIP) for the selective solid-phase extraction (SPE) was prepared applying polymerization of pyrrole monomer in the presence of closantel (CLS) as a template molecule. The quantitative measurements were carried out using UV-Vis spectrophotometry. Several important parameters control the performance of polypyrrole sorbent. The influence of seven factors including loading time, polymerization time, amount of sorbent, stirring rate, desorption time, initiator concentration and monomer to template ratio were investigated. The optimization of parameters was performed using Plackett-Burman design (PBD), central composite design (CCD), artificial neural network (ANN) and genetic algorithm (GA). The Pareto plot showed that the effects of loading time, reaction time and amount of sorbent are most important to the process. These significant factors were investigated using CCD and the obtained data were used to train the ANN. The predicted model obtained from the trained ANN was introduced to GA as the fitness function to be optimized. The calibration curve demonstrated linearity over a concentration range of 0.010-10 mM with a correlation coefficient (R²) of 0.9833 under optimal condition. The synthesized MIP sorbent showed a good selectivity and sensitivity toward CLS. The limit of detection (LOD) for CLS was obtained 1.0 μM. The real sample analysis was performed to determine CLS in pharmaceutical and human serum samples.

An environmentally friendly and novel amine-based liquid phase microextraction of quercetin in food samples prior to its determination by UV-vis spectrophotometry

A novel and environmentally-friendly method, which includes determination of trace amounts of quercetin in samples by using UV-vis spectrophotometry after enrichment with amine-based liquid phase microextraction (LPME), has been developed. As extraction solvent, N,N-dimethyl-n-octylamine has been used and the quercetin concentration in extraction phase was determined by UV-vis spectrophotometry at 382.5 nm. Important analytical parameters such as pH, extraction solvent type and volume, sample volume, extraction time were optimized by the method. Quercetin in the sample solution was extracted to 200 μL of N,N-dimethyl-n-octylamine phase at pH 4.0. The detection limit (LOD) and the quantitation limit (LOQ) values for quercetin were calculated as 0.07 μg·mL^-1 and 0.24 μg·mL^-1, respectively. Accuracy studies for the food samples was carried out by addition and recovery experiments. The developed method has been successfully applied to different food samples including spinach, green pepper, red onion and dill weed.

Rapid ultrasound-assisted microextraction of atorvastatin in the sample of blood plasma by nickel metal organic modified with alumina nanoparticles

In the present work, nickel-1,4-benzenedioxyacetic acid was synthesized as a rod-like metal organic material and then modified with alumina nanoparticles to synthesize nickel metal organic modified-Al₂ O₃ nanoparticles. The material was found as an efficient sorbent for the enrichment of atorvastatin in human blood plasma. After the extraction of the sample of plasma by ultrasound-assisted dispersive solid phase extraction, high performance liquid chromatography-ultraviolet was used to determine the quantitatively pre-concentrated interest analyte. The conditions for optimum extraction were achieved by the optimization of the volume of eluent, dosage of the sorbent, and time of sonication. Solution pH of 7.0, 250 μL of ethanol, 45 mg of the sorbent, and 10 min of sonication time were the conditions for extracting the atorvastatin maximum recovery of higher than 97.0%. By using desirability function for the optimization of the process, the present method showed a response that was linear ranging from 0.2 to 800 ng/mL with regression coefficient of 0.999 in the plasma of human blood with a satisfactory detection limit of 0.05 ng/mL, while the precision of interday for the current method was found to be <5%. It can be concluded that dispersive solid phase extraction method is effective for the extraction of atorvastatin from human plasma samples (97.4-102%) due to its easy operation, simplicity, repeatability, and reliability.

An alkaline dissolution-based method using tetramethylammonium hydroxide for metals determination in cow milk samples

This study approaches the development of a method for the determination of Ca, Mg, Zn, and Fe in liquid and powdered cow milk. The method is based on sample dissolution assisted by ultrasound energy in tetramethylammonium hydroxide (TMAH) media and determination by flame atomic absorption spectrometry (FAAS). Central composite design (CCD) associated with response surface methodology and desirability function allowed the fast and efficient optimization of the variables involved in the performance of the dissolution. The developed dissolution method allowed Ca, Fe, Zn, and Mg determination in milk samples with adequate analytical characteristics for these determinations. Addition/recovery tests and analysis of a certified reference material of skimmed powdered milk (ERM-BD150) have shown that this method presents enough accuracy to carry out these analyses.

Biocompatible chitosan-zinc oxide nanocomposite based dispersive micro-solid phase extraction coupled with HPLC-UV for the determination of rosmarinic acid in the extracts of medical plants and water sample

In the present research, a procedure was described for the recovery of rosmarinic acid (RA) from medical extract samples using chitosan‑zinc oxide nanoparticles as a biocompatible nanocomposite (CS-ZnO-NC). The dispersive micro-solid phase extraction (D-μ-SPE) of RA from the medical extract samples was investigated by using the prepared biocompatible composite as a solid phase. The HPLC-UV method was used for measuring the extracted RA. The important variables (pH, biocompatible composite mass, contact time, and volume of eluent) associated with the extraction process were analyzed by the application of central composite design (CCD). The achieved optimum values for the mentioned variables were 7.0, 10 mg, 4 min, and 180 μL, respectively. The extraction recovery (99.68%) obtained from the predicted model was in agreement with the experimental data (98.22 ± 1.33%). In addition, under the obtained optimum conditions and over the concentration in the range of 2-3500 ng mL-1, a linear calibration curve was obtained with R2 > 0.993. The limit of detection (LOD) and quantification (LOQ) values were computed, and the obtained ranges were respectively from 0.060 to 0.089 ng mL-1 and 0.201 to 0.297 ng mL-1. In addition, the enrichment factors were obtained in the range of 93.7-110.5 with preconcentration factor of 83.3. Therefore, the D-μ-SPE-HPLC-UV method could be used for analyzing RA in the samples of the extracts obtained from the medical plants and water with the recovery values of the analyte in the range of 96.6%-105.4% and the precision with relative standard deviation <5.7%.

Extraction of triterpenoid compounds from Ganoderma Lucidum spore powder through a dual-mode sonication process

Development of drug products from natural sources enable advantageous treatment and therapy options. Bioactive compounds in Ganoderma lucidum spore powder (GLSP) are known for vast antibacterial, antioxidant and anti-cancer properties. Herein, we studied the use of dual-probe ultrasound to extract triterpenoids from GLSP and further investigated the bioactivity of resulting products. FTIR results confirm the presence of key peaks although dual-probe ultrasound varied extraction efficacy. Response surface methodology (RSM) was used to optimize extraction conditions (55:28 for solvent to solid ratio, 10.38 s of ultrasound time and 94% v/v of ethanol concentration). HPLC-Q-TOF-MS confirmed the presence of nine different compounds and in vitro tests confirm good biocompatibility. Extracts are shown to inhibit DPPH radicals, reaching a maximum (61.09 ± 1.38%) at triterpenoid concentrations of 600 µg/mL. Dual-mode assisted extraction provides an enhanced approach for active embedded fiber production on a scale favorable to industry when using optimized process parameters. Furthermore, triterpenoid extracts show antibacterial properties on Staphylococcus aureus and Escherichia coli with potential in antibacterial and anticancer applications.

Ultrasonic-assisted recycling of Nile tilapia fish scale biowaste into low-cost nano-hydroxyapatite: Ultrasonic-assisted adsorption for Hg2+ removal from aqueous solution followed by "turn-off" fluorescent sensor based on Hg2+-graphene quantum dots

This study was planned to recycle calcium and the phosphorus-rich Nile tilapia fish scale biowaste into nano-hydroxyapatite (FHAP), using ultrasonic-assisted extraction of calcium and phosphorus from fish scales, which was optimized in term of extraction time, acid concentration, extraction temperature, and ultrasonic power. These two elements were determined simultaneously by inductively coupled plasma atomic emission spectrometry and the FHAP phase was formed upon addition of the extracted element solution in alkaline medium using homogenous precipitation assisted with ultrasound energy. The FHAP adsorbent was characterized by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller. A combination of FHAP and the ultrasonic method was then used to remove Hg²⁺ from aqueous solution. Four significant variables affecting Hg²⁺ removal, namely, adsorbent dosage, pH, ultrasonic power, and adsorption time, were studied. The results exhibited that the optimal conditions for maximizing the removal of Hg²⁺ were 0.02 g adsorbent dosage, pH 8, 0.4 kW ultrasonic power, 20 min adsorption time, and 30 °C adsorption temperature. The sorption mechanism of Hg²⁺ was revealed by isotherm modeling, indicating that FHAP adsorbent has a potential for Hg²⁺ removal in aqueous media with the maximum adsorption capacity being 227.27 mg g^-1. This adsorption behavior is in agreement with the Langmuir model as reflected by a satisfactory R² value of 0.9967, when the kinetics data were fitted with pseudo-second-order. Therefore, the FHAP could be an alternative adsorbent for the ultrasonic-assisted removal of Hg²⁺ at very high efficiency and within a very short period of time.

Sr-Doped NiO3 nanorods synthesized by a simple sonochemical method as excellent materials for voltammetric determination of quercetin

A fabricated Sr-doped NiO₃ nanorod-modified GCE was developed for electrochemical sensing of quercetin.

Optimization of membrane modification using SiO2 for robust anti-fouling performance with calcium-humic acid feed in membrane distillation

The goal of this study was to prepare a robust anti-wetting and anti-fouling polyethersulfone (PES) membrane for the rejection of a highly saline (NaCl and CaCl₂·2H₂O) feed solution containing humic acid (HA) in direct contact membrane distillation (DCMD). Response surface methodology (RSM) was used to determine the optimum formulation of the used materials. The variable factors selected were polydimethyl siloxane (PDMS) and silica (SiO₂); liquid entry pressure (LEP) and contact angle (CA) were selected as responses. Scanning electron microscopy (SEM) analysis confirmed the SiO₂ deposition and Fourier-transform infrared spectroscopy (FTIR) test evidenced the new functional groups i.e., Si-OH, siloxane, and C-F bond vibrations at 3446, 1099 cm^-1, and 1150-1240 cm^-1 respectively on the membrane surface. The average roughness (Ra) was increased four times for the coated membranes (0.202-0.242 µm) as compared to that for pristine PES membrane (0.053 µm). The optimum PES-13 membrane exhibited consistent flux of 12 LMH and salt rejection (> 99%) with anti-fouling characteristic in DCMD using the feed solution of 3.5 wt% NaCl + 10 mM CaCl₂·2H₂O + 10 mg L^-1 HA. The PES-13 membrane may therefore be a key membrane for application in DCMD against CaCl₂·2H₂O-containing salty solutions with HA.

Ultrasound combined with manganese-oxide nanoparticles loaded on activated carbon for extraction and pre-concentration of thymol and carvacrol in methanolic extracts of Thymus daenensis, Salvia officinalis, Stachys pilifera, Satureja khuzistanica, and mentha, and water samples

A dispersive micro solid-phase extraction (DMSPE) technique was developed using manganese-oxide nanoparticles loaded on activated carbon (Mn₃O₄-NPs-AC) as an effective sorbent combined with ultrasound for the extraction and determination of a trace amount of thymol and carvacrol in methanolic extracts of Thymus daenensis, Salvia officinalis, Stachys pilifera, Satureja khuzistanica and mentha, and water samples.

Dispersive micro-solid phase extraction based on Fe3O4@SiO2@Ti-MOF as a magnetic nanocomposite sorbent for the trace analysis of caffeic acid in the medical extracts of plants and water samples prior to HPLC-UV analysis

In this work, Fe₃O₄@SiO₂@Ti-MOF-NCs, as an efficient sorbent, have been synthesized in a laboratory and utilized for extracting CA in the medical extracts of plants and water samples before their analysis by HPLC.

Magnetic dispersive micro-solid phase extraction with the CuO/ZnO@Fe3O4-CNTs nanocomposite sorbent for the rapid pre-concentration of chlorogenic acid in the medical extract of plants, food, and water samples

CuO/ZnO@Fe₃O₄-CNTs-NC was synthesized and used as a sorbent in a MDMSPE method for the determination of chlorogenic acid in the medical extract of plants, food, and water samples.

Facile synthesis, growth process, characterisation of a nanourchin-structured α-MnO2 and their application on ultrasonic-assisted adsorptive removal of cationic dyes: A half-life and half-capacity concentration approach

Textile dyes pose a serious threat in terms of water pollution due to its complex aromatic structures and poor degradability. In order to reduce the toxic effects of Crystal Violet (CV) and Methylene Blue (MB), an ultrasonic-assisted dye adsorption using urchin like α-MnO₂ nanostructures was studied. The adsorbent was synthesised by hydrothermal method at low-temperature. The crystallinity and morphology were determined to investigate the growth mechanism of α-MnO₂ nanourchins which consists of two main stages. The initial stage includes the formation of α-MnO₂ microspheres followed by the epitaxial growth of nanoneedles on to the surface of them. The α-MnO₂ was characterised by BET, XRD, FT-IR, XPS, SEM, TEM and TGA. At 5.6, the point of zero charge of α-MnO₂ nanostructures was determined. The total pore volume and average pore radius were confirmed to be 4.751 × 10^-2 cc/g and 10.99 Å respectively from the BET analysis. Batch adsorption experiments were performed to investigate the effect of pH, adsorbent dosage, sonication time, initial dye concentration, temperature, ultrasonic frequency and power. The adsorption mechanism was studied using several isotherm and kinetic models. The adsorption data of CV and MB at equilibrium was observed to adopt the Langmuir isotherm model and pseudo-second order kinetic model. The maximum adsorption capacities for CV and MB were found to be 5882.3 and 5000 mg/g respectively. The thermodynamic study predicted that the process was exothermic for CV and endothermic for MB. The effects of competitive ions, ionic strength and humic acid on the uptake of both the dyes were also investigated. And finally, the reusability of recovered α-MnO₂ after dye adsorption was studied up to five cycles for its potential industrial applications.

Ultrasonic power improvement of flumequine degradation effectiveness in aqueous solution via direct and indirect action of mechanical acoustic wave

The current research work aimed to describe the roles of ultrasonic power under sono-Fenton process in the degradation of flumequine (FLU) in water. For this purpose, the effects of some parameters including temperature, ferrous ion concentration, chemical oxidant concentration (S₂O₈^2- and Cl^-) and the initial pH value of the reaction kinetics were investigated. Results showed that the degradation of FLU antibiotic was accelerated by ultrasonic irradiation and the presence of an inorganic oxidant. The sono-generation of active species such as hydroxyl radicals (HO and HOO) and sulfate radicals (SO₄^-) as strong oxidizing agents improved the FLU degradation. In fact, the peroxydisulfate anion (S₂O₈^2-) has been identified as among parameters that enhanced the degradation process. Under optimal conditions, 98% of the flumequine removal was carried out within 80 min at 60 °C.