Water-based Solution Research Articles

Niosomes: A promising approach for targeted drug delivery

Niosomes, also known as nonionic surfactant vesicles, are small lamellar structures that are created by combining nonionic surfactants from the alkyl or dialkyl polyglycerol ether category with cholesterol, and then hydrating them in water-based solutions. These are vesicle systems resembling liposomes that can be utilized as carriers for drugs that are both amphiphilic and lipophilic. The production process of niosomes is derived from liposome technology. The fundamental manufacturing method remains unchanged, wherein the lipid phase is hydrated by the aqueous phase. The lipid phase can consist of either a pure surfactant or a combination of surfactant and cholesterol. Niosomes effectively tackle the challenges associated with medication insolubility, instability, inadequate bioavailability, and fast degradation. The amphiphilic character of niosomes, which combines both hydrophilic and lipophilic properties, enhances their capacity to encapsulate medicines that are either hydrophilic or lipophilic. Cholesterol is frequently utilized as one of the ingredients. Preserving the stiffness of the niosome structure. The present article discusses the essential elements of niosomes, including their structural constituents, methods of manufacturing, and their uses in different disorders.

Investigation of Cephalexin Removal Using Biochar Derived from Nephelium lappaceum Seeds

<p class="MsoNormal" style="line-height:200%;margin-bottom:0cm;mso-layout-grid-align:none;text-align:justify;text-autospace:none;"><span style="font-family:"Times New Roman",serif;font-size:12.0pt;line-height:200%;" lang="EN-US">The improper disposal of drugs into bodies of water has become a severe environmental and health issue. Biochar synthesized from different agro residues could be a potential material for the adsorption of pollutants in aqueous environments. </span><em><i style="mso-bidi-font-style:normal;"><span style="font-family:"Times New Roman",serif;font-size:12.0pt;line-height:200%;" lang="EN-US">Nephelium lappaceum</span></i></em><span style="font-family:"Times New Roman",serif;font-size:12.0pt;line-height:200%;" lang="EN-US"> seeds were pyrolyzed at 600 °C in a pyrolysis reactor incorporating a slow pyrolysis process for carbonization. Fourier-Transform Infrared (FTIR), Scanning Electron Microscope (SEM), and X-ray diffraction (XRD) were used to characterize the biochar before and after adsorption of the pharmaceutical pollutant cephalexin. The effects of several factors, including initial cephalexin concentration, time of contact, dosage of adsorbent, and pH, were considered for the sorption. The findings showed that the Freundlich model offered the greatest fit for adsorption. The better-fitted kinetic model was the pseudo-second-order kinetic. Based on Langmuir isotherm model, the maximum adsorption capacity of cephalexin was obtained as 63.69 mg/g. The adsorption process involves hydrogen bonding, surface complexation, electrostatic and π−π EDA interactions. The current study offers a feasible and optimistic method for using agricultural waste and an alternative adsorbent substance for recovering highly concentrated cephalexin from water-based solutions.<o:p></o:p></span></p>

Adsorption technique using new semi-IPN hydrogels for high removal of methylene blue dye from aqueous solutions

ABSTRACT Six new semi-IPN hydrogels using 2-acrylamido-methylpropane-1-sulfonic acid (AMPS) and Gelatin at different ratios through redox polymerization were prepared. Methylene-bisacrylamide and glutaraldehyde were used as the crosslinking agents for AMPS and Gelatin, respectively. The hydrogels’ swelling ratios and surface morphologies were analyzed using SEM for characterization. Porosity and specific surface area using the Brunauer–Emmett–Teller technique. DSC and Tg were also used for the thermal analysis of the prepared hydrogels, which show trans-glass temperature (Tg) higher than their raw materials AMPS and Gelatin. The prepared hydrogels were used to eliminate the cationic dye MB from the water-based solutions with an initial concentration of 600 ppm. The study discovered that the N9 and N10 hydrogels were extremely effective at removing a certain dye from aqueous solutions with an optimum pH level of 11 and an optimum temperature of 65°C. Both N9 and N10 achieved high removal efficiencies, reaching equilibrium at 90 min, whereas the other hydrogels required 120 min. N9 performed slightly better at 1078.919 mg/g and N10 at 1057.404 mg/g. The adsorption behavior of the two hydrogels followed the Langmuir model. The hydrogels exhibited pseudo-second-order kinetics. The thermodynamic study cleared that the adsorption of MB dye was endothermic and spontaneous. Results also showed that the adsorption of dyes with hydrogels N9 and N10 is chemisorption in nature. Desorption studies were conducted using 0.1 M HCl and NaOH. HCl was found to be the best eluent for dye recovery.

Entropy generation analysis of unsteady MHD nanofluid flow in a porous pipe

This article presents a numerical investigation into the entropy production of nanofluids flowing through a porous medium in a permeable conduit, focusing on water-based solutions containing Titanium Carbide (TiC) and Silicon Carbide (SiC) nanoparticles. These nanoparticles are selected for their heat transfer properties. The flow system's governing equations are developed and solved using the Runge-Kutta-Fehlberg method. The study examines the influence of key nondimensional parameters, including the solid volume fraction of nanoparticles, radiation parameters, and Reynolds number, on temperature, velocity profiles, and entropy generation. The results show that Silicon Carbide-water nanofluids perform efficiently in terms of heat transfer and entropy minimization. Additionally, Silicon Carbide exhibits low skin friction at the pipe wall, with this effect increasing as the solid volume percentage of nanoparticles rises. The study also indicates that irreversibility due to heat transfer becomes more significant near the pipe wall as the solid volume fraction decreases and increases with higher radiation parameters and Reynolds number. These findings are presented graphically and in tabular form to illustrate the physical significance of the problem.

Experimental investigation of CO2 capture at high pressure using energy-efficient amino acid salt solvents

The increase in energy consumption has led to greenhouse gas emissions, specifically CO2. This has caused many researchers to explore the possibility of capturing CO2 emissions. The utilization of typical water-based solvents, such as amine solutions, poses challenges in large-scale operations owing to the substantial energy consumption associated with their regeneration process. To decrease the energy required to regenerate the solvent, new types of phase change solvents, known as lean water amino acid-based phase change solvents, were invented. This study investigated the absorption capacity of an amino acid salt made up of glutamine and potassium hydroxide in a water-based solution including N,N-dimethylformamide (DMF) as a co-solvent. The measurement of absorption capacity was conducted under elevated pressures ranging from 5 to 30 bar. Additionally, an investigation was conducted to assess the impact of DMF volumetric concentration on absorption capacity. The findings of the study indicated that augmenting both the pressure and concentration of DMF increased the capacity for CO2 absorption. This enhancement was achieved by simultaneously raising the rates of physical and chemical absorption. The results obtained from the C NMR phase analysis revealed that the solid phase had carbon bonds that were related to the absorption of CO2, whilst the upper liquid phase did not contain any CO2. This phase might readily be recycled into the absorption process without the need for regeneration. The absorption capacity of this solvent was also assessed following three absorption-reduction cycles. The results indicated a decrease in absorption capacity by only 6.6 %.

Green Synthesis of New Derivatives of Iminothiazole Using Cefixime and Removing Organic Pollutants from Aqueous Environment by Employing Cu@KF/Clinoptilolite NPs.

In this research, multicomponent reactions of cefixime, isothiocyanates, and alkyl bromides were carried out for the synthesis of new iminothiazole derivatives with high yields in water as the solvent at room temperature in the presence of catalytic amounts of Cu@KF/CP NPs as catalysts. Also, the ability of Cu@KF/Clinoptilolite nanoparticles (NPs) to adsorb and remove 4-NP and cefixime from water was investigated. The Cu@KF/Clinoptilolite nanoparticles were synthesized by employing a water extract of Petasites hybridus rhizomes. For this experiment, all of the components obtained from Fluka and Merck were subjected to further purification. The antibiotic used in this investigation, cefixime, was obtained from a pharmaceutical facility situated in Sari, Mazandaran, Iran. The antibiotic factory is located in Sari City, Iran. All solutions were prepared using distilled water. The shape of Cu@KF/CP nanoparticles was analyzed using images obtained from a Holland Philips XL30 scanning electron microscope. An analysis was performed on the crystalline structure of Cu@KF/CP nanoparticles (NPs), and a room temperature X-ray diffraction (XRD) examination was carried out utilizing a Holland Philips Xpert X-ray powder diffractometer. The X-ray diffraction (XRD) examination was conducted using CuK radiation, which has a wavelength of 0.15406 nm. The analysis covered a 2ε angle range from 20 to 80°. The nanostructures that were produced were chemically analyzed using X-ray energy dispersive spectroscopy (EDS) with an S3700N equipment. The morphology and dimensions of Cu@KF/CP nanoparticles were characterized using a Philips EM208 transmission electron microscope operated at an acceleration voltage of 90 kV. The primary objective of this study was to develop a sustainable approach for producing new iminothiazole derivatives 4. This was achieved using a highly efficient three-component reaction combining cefixime 1, isothiocyanates 2, and alkyl bromides 3. The reaction was carried out in water at ambient temperature, using Cu@KF/CP NPs as a highly effective catalyst, leading to excellent yields. Moreover, the study findings showed that the synthesized compounds demonstrated a significant antioxidant activity compared to conventional antioxidants. The antibacterial efficacy of the synthesized compounds was evaluated against both Gram-positive and Gram-negative bacteria. Furthermore, Cu@KF/CP nanoparticles were utilized to adsorb CFX and 4-NP from water-based solutions. This study showcases the effective synthesis of innovative iminothiazole derivatives through the use of multicomponent reactions, involving the combination of cefixime, isothiocyanates, and alkyl bromides. The reactions were conducted in a water-based solvent. The reactions were carried out at room temperature, utilizing Cu@KF/CP NPs as catalysts. The Cu@KF/CP nanoparticles, a newly developed heterogeneous nanocatalyst, were synthesized and evaluated utilizing X-ray diffraction (XRD), fieldemission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) research techniques. Cu@KF/CP nanoparticles are utilized to adsorb CFX and 4-NP from water-based solutions. The objects were manufactured using a straightforward and uncomplicated approach. The BET surface area of Cu@KF/CP NPs was measured to be 201.8 m2/g. The experimental equilibrium data was evaluated by applying the isotherms of the Langmuir, Freundlich, Dubinin-Radushkevich, and Redlich-Peterson models. Additionally, we examined the catalytic efficiency of Cu@KF/CP nanoparticles (NPs) in reducing various colors in water.

Natural surfactant used as an additive in the enzymatic-homogenate synergistic extraction of piceatannol, resveratrol, and myricetin from the myrtle (Rhodomyrtus tomentosa) fruit

In this study, three different target analytes from the fruit of myrtle (Rhodomyrtus tomentosa) were extracted via an enzymatic-homogenate synergistic extraction (EHSE) process, and 10 different aqueous solutions of natural surfactants were selected as extraction solvents, thus enabling the simultaneous extraction of piceatannol, resveratrol, and myricetin from the fruit of myrtle (Rhodomyrtus tomentosa). Important factors affecting the yield of piceatannol, resveratrol, and myricetin, including enzyme type, enzyme concentration, pH, surfactant type and dosage, homogenization time, liquid‒solid ratio, incubation and extraction time, incubation time and extraction temperature, were optimized via single-factor experiments. Three important parameters were optimized via the Box‒Behnken design: the liquid‒solid ratio, the incubation–extraction time, and the reaction temperature. The final optimum extraction process conditions were as follows: β-glucosidase concentration, 3.0%, homogenate; time, 3 min; pH, 5; tea saponin concentration, 0.8%; liquid‒solid ratio, 45 mL/g; incubation–extraction time, 2.5 h; and temperature, 67.5 °C. With the optimized experimental parameters, the piceatannol, resveratrol, and myricetin yields were 742.12 ± 37.11 μg/g, 18.58 ± 0.94 μg/g, and 24.83 ± 1.25 μg/g, respectively. Methodological validation and comparison experiments with traditional solvents demonstrated that EHSE is a successful, green, and safe method for extracting active plant components. This approach employs an ecologically benign water-based solution of tea saponin as the extraction solvent, and it combines enzymatic and homogenate procedures to increase extraction efficiency. This study provides a reasonable basis for the application and research of synergistic extraction technology and suggests that more diverse solvent choices should be considered.

Chitin membrane for efficient laccase immobilization and synergistic removal of 17α-ethynylestradiol from water-based solutions

A unique chitin–laccase membrane was fabricated as an environmentally friendly biocatalytic platform, utilizing 1-butyl-3-methylimidazolium acetate as the solvent for chitin. Observations using scanning electron microscopy showed that the chitin-laccase membrane possessed a uniform and densely packed structure. Based on the presence of FT-IR signals at 1020 cm−1 and changes in the intensity of signals at 1540 cm−1 and 1645 cm−1, the effectiveness of laccase immobilization was confirmed. FT-IR mapping revealed that the enzyme is evenly distributed on the surface of the membrane. The catalytic activity of the native enzyme and laccase immobilized using the membrane was determined based on a model reaction, and the retention of high activity was confirmed using real solutions. Laccase immobilized using the chitinous membrane retained over 60 % of its initial activity after 30 days of storage at 4 °C. By contrast, the free enzyme retained <40 % of its initial activity. Moreover, the activity of chitin-laccase system remained at 85 % after 5 cycles. This novel chitin–laccase combination was tested in the 17α-ethynylestradiol (EE2) removal from water-based solutions. It was found that EE2 underwent synergistic degradation through concurrent adsorption and biocatalytic transformation, with enzymatic conversion as the dominant mechanism.

Chemical analysis and performance evaluation of ClearCorrect® aligners as received and after intraoral use: Implications for durability, aesthetics, and patient safety

BackgroundOrthodontic treatment with transparent aligners is popular with patients. Any alteration of the plastic material, as subjected to the oral environment, could influence the treatment's durability, the aligner's aesthetic appearance, and the patient's safety. PurposeThis study concerns the physicochemical properties of ClearCorrect® aligners before and after intraoral use, focusing on transparency, surface topography, leachable, polymer glass transition temperature, and viscoelastic properties. MethodsAligners were collected after two weeks of intraoral use. Unused samples were obtained from the manufacturers. Transparency was measured by UV–visible spectroscopy. Chemical modifications were studied using infrared and Raman spectroscopies. Thermal degradation, glass transition (Tg), and storage modulus (E') were characterized by thermal analysis (DSC, TGA, DMA). Surface morphology and roughness were studied thanks to SEM and AFM. Aligners were immersed in water-based solutions to identify and quantify organic leachable by HPLC chromatography and trace elements by atomic absorption spectroscopy. ResultsClearCorrect® aligners have a three-layer structure (outer PETG/inner PU layers). Slight chemical alterations occurred after aging. There was also no significant evolution in Tg and thermal degradation temperatures and only a minimal evolution of E'. Surface and transparency alterations occurred. A difference in organic compound and trace element release levels between new and used aligners was evidenced, suggesting an intraoral release during use. SignificanceIntra-oral aging mainly impacts the aligner transparency and surface. The leachable study suggests significant ingestion of organic and non-organic compounds by the patient: investigations are needed to assess the impact of the long-term use of trays on patient health.

Nanostructured bi-metallic biochar: An innovative approach for arsenic (III) removal from contaminated water

Possessing variable valence states, the element Arsenic (As) is intimidating the quality of the ecology and human health severely. In this study, eliminating As (III) from water-based solutions with great efficiency was done using Bagasse-Mn-Al, a sugarcane bagasse-derived biochar impregnated with Mn and Al. The Bagasse-Mn-Al composite yielded higher removal efficiency towards As (III) than the biochar itself. About 89.53 % of As (III) was removed within 65 min maintaining the very first concentration of As (III) at 400 μg/L, initial pH at 2–2.5, and adsorbent dosage at 0.625 g/L. The Bagasse-Mn-Al composite showed an adsorption potential maximum of 54.945 mg/g which is superior to most of the cheaply synthesized metal-impregnated biochar reported. Results from a variety of characterization techniques indicated that the •OH free radical in the Bagasse-Mn-Al composite mainly contributed to the removal of As (III) where oxidation and complexation were the major mechanisms. With high catalytic efficiency, this cost effectively produced metal-coated biochar showed easy and effective separation of As (III) from aqueous solution. Further, this study focuses on the high potential of Bagasse-Mn-Al adsorbent in the treatment of both ground and wastewater.

Revolutionizing sensing technologies: Crafting a green, ultra-sensitive bismuth optical sensor via fixation of 5-(2′,4′-dimethyl-phenylazo)-6-hydroxypyrimidine-2,4-dione on PVC membrane

An innovative and exceptionally responsive optical sensing device engineered to selectively identify Bi(III) ions in water-based solutions. The sensing component, 5-(2′,4′-dimethylphenylazo)-6-hydroxypyrimidine-2,4-dione (DMPAHPD), is incorporated into a plasticized polyvinyl chloride (PVC) membrane. The sensor demonstrates an exceptional selectivity for Bi(III) within a broad dynamic range spanning from 7.5 × 10−10 to 4.2 × 10−5 M at pH 2.25. Notably, it achieves lower quantification and detection limits of 7.25 × 10−10 and 2.15 × 10−10 M, respectively. The optode membrane’s response to Bi(III) proves to be entirely reversible, demonstrating remarkable selectivity for Bi(III) ions over a diverse range of other cations and anions. The sensor exhibits favorable performance characteristics, including good reversibility, a wide dynamic range, a prolonged lifespan, sustained response stability over the long term, and high reproducibility. This visual chemical sensor exhibits potential for real-world usage, offering consistent outcomes when assessing Bi(III) levels in matrices such as water, soil, plants, biological and synthetic mixtures. Importantly, the sensor’s performance is comparable to corresponding data achieved from inductively coupled plasma atomic emission spectroscopy (ICP-AES).

Highly efficient adsorption of eosin yellow dye from aqueous solutions using polymer-based nanocomposite developed from cross-linked chitosan-citrate and Co2O3 nanoparticles

The utilization of polymer-based nanocomposites offers a particularly interesting method for removing organic dyes from waterways. This study aimed to efficient removal of eosin yellow (EOY) dye from aqueous solutions using polymer-based nanocomposite (hereinafter, CHA-CIT/Co2O3 NPs) prepared from crosslinked chitosan-citrate (CHA-CIT) and Co2O3 nanoparticles (Co2O3 NPs). The CHA-CIT/Co2O3 NPs adsorbent was investigated by several approaches like XRD, BET analysis, FTIR spectroscopy, FESEM-EDX, and pHpzc analysis, to get a thorough understanding of its structural and chemical characteristics. Box-Behnken design (BBD) was adopted to systematically optimize crucial adsorption parameters, including CHA-CIT/Co2O3 NPs dose (0.01–0.07 g), starting solution pH (4–10), and contact duration (10–40 min). The CHA-CIT/Co2O3 NPs nanocomposite's BET surface area was found to be 19.85 m2/g. The mean pore diameter was determined to be 4.3 nm, and the total pore volume was measured to be 0.0213 cm3/g. The average crystallite size of 23.22 nm is indicative of the CHA-CIT/Co2O3 NPs nanocomposite's mainly polycrystalline characteristics. The kinetic investigations showed an agreement with the pseudo-first-order model, while the equilibrium results agreed well with the Freundlich isotherm model, suggesting the presence of multilayer adsorption behavior. The adsorption capacity of CHA-CIT/Co2O3 NPs for EOY was found to be 650.03 mg/g at a temperature of 25 °C, highlighting its exceptional adsorption ability. The work introduces a novel and efficient chitosan nanocomposite as a potential adsorbent for the high-performance removal of organic dyes from water-based solutions.

Study of Ion-to-Electron Transducing Layers for the Detection of Nitrate Ions Using FPSX(TDDAN)-Based Ion-Sensitive Electrodes.

The development of ISE-based sensors for the analysis of nitrates in liquid phase is described in this work. Focusing on the tetradodecylammonium nitrate (TDDAN) ion exchanger as well as on fluoropolysiloxane (FPSX) polymer-based layers, electrodeposited matrixes containing double-walled carbon nanotubes (DWCNTs), embedded in either polyethylenedioxythiophene (PEDOT) or polypyrrole (PPy) polymers, ensured improved ion-to-electron transducing layers for NO3- detection. Thus, FPSX-based pNO3-ElecCell microsensors exhibited good detection properties (sensitivity up to 55 mV/pX for NO3 values ranging from 1 to 5) and acceptable selectivity in the presence of the main interferent anions (Cl-, HCO3-, and SO42-). Focusing on the temporal drift bottleneck, mixed results were obtained. On the one hand, relatively stable measurements and low temporal drifts (~1.5 mV/day) were evidenced on several days. On the other hand, the pNO3 sensor properties were degraded in the long term, being finally characterized by high response times, low detection sensitivities, and important measurement instabilities. These phenomena were related to the formation of some thin water-based layers at the polymer-metal interface, as well as the physicochemical properties of the TDDAN ion exchanger in the FPSX matrix. However, the improvements obtained thanks to DWCNT-based ion-to-electron transducing layers pave the way for the long-term analysis of NO3- ions in real water-based solutions.

Development of a process for extracting rare earth elements from phosphogypsum by dissolving them in deep-eutectic solvent

ABSTRACT The exploitation of deep-eutectic solvents (DESs) offered a potential substitute for water-based solutions when it came to leaching REEs from phosphogypsum (PG). The REEs leachate from PG obtained by DES which comprised choline chloride (ChCl) and diglycolic acid (DGA) or lactic acid (LA). The data offered a successful method for REEs leaching by DES ChCl:LA. The optimal leaching conditions included 150 min, 70°C, ChCl:LA 1:2 molar ratio of 800 rpm, a 15:1 L/S ratio, and 15% additional water. Cyanex 923 was used to assess REEs extraction from DES leachate. The best parameters were 900 rpm, 0.8 M Cyanex/toluene at 25°C, with 15 min extraction time and 1/1 A/O ratio. The REEs were stripped from the REEs/Cyanex after equilibrating for 20 minutes using 0.7 M citric acid, 1/2 A/O ratio, and 1000 rpm at 25°C. The RE ions precipitated from the obtained stripping solution by 30% oxalic acid and pH 1. The RE oxalate was precipitated and then burned at 700°C to gain RE oxide. The RE oxide powder was subjected to analysis to determine the REEs; it was possible to determine that the REEs were 80.98% in RE oxide concentrate, resulting in a purity of 94.76%.

Ultrasonic and volumetric investigation of aqueous disodium EDTA with PEG 400 and PEG 4000 at different temperatures

Polyethylene glycol (PEG) 400 and 4000 thermodynamic characteristics in water-based disodium ethylenediaminetetraacetic acid solutions provide important clues about the nature of the intermolecular interactions taking place in this liquid environment. In order to make these determinations, the present study reports data for density and sound velocity at a variety of temperatures and then analyses the volumetric-acoustic features of the solutions. The experimental data for PEG 400 and PEG 4000, which are polyethylene glycols, were recorded at a constant atmospheric pressure of 0.1 MPa and at temperatures ranging from 288.15 to 318.15 K. The values were 0.007, 0.008, and 0.009 mol·kg−1. From the experimental density and speed of sound values, the following are computed: apparent molar properties, partial molar properties, partial molar transfer properties, and the partial molar expansibility, along with its first derivative and thermal expansion coefficient. According to the co-sphere overlap model, the results are described using these generated parameters, these are thought of as the type of interactions taking place within the combination. This study also uses partial molar characteristics to assess the pair interaction coefficients and triplet interaction coefficients.

Methylene blue removal using nano-TiO2/MWCNT/Chitosan hydrogel composite beads in aqueous medium

Dyestuff, one of the most hazardous compounds in terms of threats to people and the environment, is found in wastewater from industrial usage. The removal of Methylene Blue (MB) from a water-based medium has been studied by numerous researchers using a variety of adsorbents. To remove MB from aqueous solution, nano-TiO2/MWCNT/Chitosan hydrogel composite beads (n-TiO2/MWCNT/Cht) were developed in this study using a sol-gel method. This research discusses the characterisation of a new adsorbent substance using Infrared Spectroscopy (FT-IR) analysis and scanning electron microscopy (SEM). The optimal pH, adsorbent dosage, duration, and starting concentration were ascertained by analyzing the removal efficiencies of MB using the batch adsorption method. Adsorption behaviour at the equilibrium state has been investigated using a variety of adsorption isotherms, including Freundlich, Langmuir, and Dubinin-Radushkevich. The Langmuir adsorption isotherm has been useful to clarify adsorption behaviors. nTiO2-Cht/MWCNT had an adsorption capacity of 80.65 mg/g for MB. The pseudo-second-order kinetic model offered the best agreement to the experimental data for the adsorption of MB. Kinetic models of pseudo-first-order and pseudo-second-order were employed to explore the adsorption processes of MB on the n-TiO2/MWCNT/Cht. This study demonstrated the efficiency of n-TiO2/MWCNT/Cht for the removal of MB from a water-based solution.

Optimisation and validation of cost-effective water-based solutions of acid fuchsin for detecting fingermarks in blood

Fingermark impressions in blood are commonly encountered at violent crime scenes and represent a critical trace that can link an individual to the scene. A range of techniques are available for detecting and enhancing bloody impressions; however, many chemical methods involve using hazardous solvents or require alternative light sources to visualise fluorescence. This is particularly challenging for bloody impressions on dark substrates. An alternative treatment is the protein dye known as acid fuchsin (commonly known as ‘Hungarian Red’), which can be visualised under both white light and fluorescence lighting. However, there is limited research available on this method, especially concerning its use in detecting bloody fingermarks on dark surfaces and its fluorescence qualities. To address these knowledge gaps, this study broadly aimed to evaluate the effectiveness of acid fuchsin for enhancing bloody fingermarks on a range of common substrates, along with comparing the performance of a formulation made from base components against a commercially-available Hungarian Red reagent. Through a multi-phased experimental approach, results supported an all-in-one treatment that contained 2 % SSA, 0.2 % acid fuchsin, and deionised water as the most effective. This formulation performed as well or better than commercial Hungarian Red, amido black and acid yellow in the validation trial. Enhanced impressions could be visualised under white light on light and dark surfaces, whilst 530 nm excitation provided improved detection via both fluorescence and absorption modes depending on substrate background interference. Moreover, the reagent was applied by spraying directly onto substrates placed at near-vertical angles, with no evidence of any fingermarks being affected by running or inadequate fixing. The ability to enhance and visualise bloody impressions on light and dark surfaces, under white light or excitation, using a single, water-based treatment is highly advantageous to operational crime scene examiners and forensic scientists.

Carbonized coffee-based 3D polymeric xerogels for freshwater recovery by solar steam generation

Interfacial solar steam generation is a promising technology for freshwater recovery from seawater desalination and water purification. Herein, is presented an eco-friendly, three-dimensional (3D) porous composite system, made from materials recovered from waste, able to desalinate and purify water upon solar irradiation. The system that consists of carbonized spent coffee powder embedded in a polyglycerol polymer matrix, is developed upon thermal curing of a water-based solution and presents an interconnected porous network with super-hydrophilic properties. We explore the effect of the 3D shape of the composite on the solar steam generation, by varying the height over the radius (aspect ratio) of the structure, and we prove that biocomposites with higher aspect ratio give rise to a progressively higher solar steam generation rate reaching, under the current conditions, 2.72 kg·m−2·h−1 for an aspect ratio of 2.2 under 1 Sun irradiation. This is attributed to the enhancement of the total area of the water–air interface which in turn facilitates the steam escape from the porous structure while, at the same time, permits to the bulk water to be effectively entrapped in the whole porous structure. This, together with the fact that the developed material can be fully biodegradable at the end of its lifespan, opens up new prospective paths for sustainable and effective clean water production.

Efficient adsorption of fluorescein dye from aqueous solutions by Al/Th-MOF bimetal-organic frameworks: Adsorption isotherm, kinetics, DFT computation, and optimization via Box-Behnken design

Bimetal-organic frameworks, or MOFs, have sparked a lot of interest in the wastewater treatment industry. This study investigated the possibility of removing fluorescein dye (FS) employing bimetal-organic frameworks based on aluminum and thorium (Al/Th-MOF) from aqueous solutions. To investigate the properties of the material further, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, surface charge analysis, and X-ray diffraction (XRD) were used. Using these methods, we were able to identify the Al/Th-MOF's point of zero charge. Following adsorption, the adsorbent's large surface area of 2273.8 m2/g and pore volume of 1.4 cm3/g drop to 1678.9 m2/g and 0.96 cm3/g, individually. As this suggests, it is ideal that a portion of the FS was absorbed within the pores of the adsorbent. Through batch testing, it looked into the connection between adsorption equilibrium and pH levels, and found that changes in solution pH significantly affected adsorption behavior. Further studies with kinetic models led to the discovery of the pseudo-second-order model for FS adsorption on Al/Th-MOF. Furthermore, the Langmuir isotherm model accurately describes the adsorption process, suggesting that chemisorption played a major role in the process as a whole. To optimize factors such adsorbent dosage, time, solution pH, the response surface methodology (RSM) and Box-Behnken design (BBD) were used. As a consequence (ΔH°), (ΔS°), and (ΔG°) data the adsorption of FS employing Al/Th-MOF as an adsorbent is endothermic and spontaneous. Our study's studies have demonstrated that the Al/Th-MOF adsorbent combines a number of mechanisms, such as π-π interaction, H-bonding, pore filling, and electrostatic contact, to effectively remove FS dye from water-based solutions. The adsorption capacity of FS onto Al/Th-MOF reaches a maximum of 668.6 mg.g−1 at a pH value of 4, demonstrating that the adsorbent is particularly successful in removing FS from wastewater samples. Furthermore, the synthesized Al/Th-MOF adsorbent possesses outstanding render ability and cyclability for a maximum of eight adsorption-desorption cycles, suggesting that it could find application as an adsorbent in industrial environments. Overall, our research suggests that the adsorbent is a potential and novel approach for managing industrial effluent and water filtering.

Degradation of 2,4-dinitrotoluene from aqueous solutions by three-dimensional electro-Fenton with magnetic activated carbon particle electrodes (GAC/Fe3O4)

Abstract 2,4-Dinitrotoluene (2,4-DNT) is a broadly applied nitroaromatic compound with multiple applications, and its simple production has resulted in its extensive utilization in producing explosives, dyes, and rubber. This substance is hazardous and induces genetic mutations in humans, fish, and microorganisms. Thus, this research was done to assess the effectiveness of the three-dimensional electro-Fenton (3D/EF) process employing magnetic activated carbon particle electrodes (GAC/Fe3O4) in eliminating 2,4-dinitrotoluene from water-based solutions. In this experimental investigation, Fe3O4 nanoparticles were created using the chemical co-precipitation technique. The G/β-PbO2 anode was fabricated by electrochemically depositing PbO2 layers on graphite sheets. G/β-PbO2 and stainless steel were utilized as the anode and cathode, respectively. The structure, particle size, and properties of the GAC/Fe3O4 nanocomposite were analyzed using FESEM, XRD, and EDX. The morphology of the G/β-PbO2 electrode was also examined using SEM. The Taguchi experimental design method was employed to identify the optimal conditions. The outcomes demonstrated that higher reaction time and current density, as well as lower pH and pollutant concentration, resulted in improved 3D/EF efficiency. Accordingly, the optimum values of parmeters were identified to be a concentration of 2,4-DNT = 50 mg/L, pH = 3, electrolysis time = 100 min, and current density = 8 mA/cm2. With these parameters, the degradation efficiency of 2,4-DNT through the examined system was 98.42 %, alongside removal efficiencies of 84.69 % for COD and 79.67 % for TOC. Additionally, the results indicated an increase in the average oxidation state (AOS) (from 1.27 to 1.95) and carbon oxidation state (COS) (from 1.27 to 2.75) in the 3D/EF process, along with a decrease in the COD/TOC ratio (from 1.81 to 1.36), indicating the effectiveness of the 3D/EF system in enhancing the biodegradability of 2,4-DNT. Overall, the combined 3D/EF process with a G/β-PbO2 anode has relatively high efficiency in degrading solutions containing DNT and can be considered a viable treatment option for wastewater containing substances such as 2,4-DNT.