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The isobaric heat capacities of acetone and its binary aqueous solutions were measured using a heat capacity meter (IT-s-400). The measurements were performed at temperatures from 323.15 to 453.15 K and pressures below 19.6 MPa for acetone and at temperatures from 348.15 to 473.15 K and the same pressures for its solutions, at concentrations of 2.5, 3.5, and 5 wt % acetone. The expanded uncertainty of heat capacity, pressure, temperature, and concentration measurements at a 95% confidence level with a coverage factor k = 2 was estimated at 2.4%, 0.05%, 15 mK, and 0.001, respectively. The results were compared with the literature data in the given ranges of state parameters. [ABSTRACT FROM AUTHOR]

Cationic porous organic polymers have a unique advantage in removing radioactive iodine from the aqueous phase because iodine molecules exist mainly in the form of iodine-containing anions. However, halogen anions will inevitably be released into water during the ion-exchange process. Herein, we reported a novel and easy-to-construct zwitterionic hypercrosslinked polymer (7AIn-PiP)-containing cationic pyridinium-type group, uncharged pyridine-type group, pyrrole-type group, and even an electron-rich phenyl group, which in synergy effectively removed 94.2% (456 nm) of I2 from saturated I2 aqueous solution within 30 min, surpassing many reported iodine adsorbents. Moreover, an I2 adsorption efficiency of ~95% can still be achieved after three cyclic evaluations, indicating a good recycling performance. More importantly, a unique dual 1,3-dipole was obtained and characterized by 1H/13C NMR, HRMS, and FTIR, correlating with the structure of 7AIn-PiP. In addition, the analysis of adsorption kinetics and the characterization of I2@7AIn-PiP indicate that the multiple binding sites simultaneously contribute to the high affinity towards iodine species by both physisorption and chemisorption. Furthermore, an interesting phenomenon of inducing the formation of HIO2 in unsaturated I2 aqueous solution was discovered and explained. Overall, this work is of great significance for both material and radiation protection science. [ABSTRACT FROM AUTHOR]

The influence of absorbed dose (up to 90 kGy) and the initial concentrations of ethylene glycol and glycerol (from 30 to 250 mg/L) on their degradation in aqueous solutions under a 3-MeV electron beam has been studied. Aeration of the solutions during irradiation decreased the yield of degradation. In the absence of aeration, the observed initial yields of degradation were about 0.23 µmol/J for ethylene glycol and about 0.14 µmol/J for glycerol. Degradation products formed in aqueous solutions are more resistant to ionizing radiation compared to the parent alcohols. A simultaneous reduction in alcohol concentration and chemical oxygen demand (COD) to standard values was achieved in solutions with an initial concentration of 30–40 mg/L at a dose of no higher than 2–3 kGy. [ABSTRACT FROM AUTHOR]

Cadmium (Cd(II)) contamination is very harmful to the aquatic environment. Currently, the removal of Cd(II) from water is widely studied to reduce its toxicity. In this study, agricultural waste sorghum bagasse (SB) was activated with NaOH and used to adsorb Cd(II) in aqueous solution. NaOH-activated sorghum bagasse (SB-NaOH) was characterised using Fourier transform infrared spectroscopy (FTIR) to investigate the functional groups, scanning electron microscopy (SEM-EDX) to observe surface morphology, X-ray diffraction (XRD) to analyzed the structure and chemical composition, and Brunauer–Emmett–Teller (BET) method to evaluate pore size. The batch system was used to investigate the adsorption parameters such as adsorbent mass, contact time, initial concentration, pH, and temperature. The optimum conditions of Cd(II) adsorption were at pH 5, 70 min, 600, 100 mg/L, and 30°C. The maximum adsorption percentage was 96.48%. The pseudo-second-order is suitable for kinetic models of Cd(II) adsorption and the isotherm model was Langmuir model. The Gibbs free energy obtained a positive value and the enthalpy had a negative value, indicating that the adsorption of Cd(II) is an exothermic process. Therefore, SB-NaOH adsorbent can be used as a potential adsorbent with easy and economical treatment to reduce Cd(II) in the aquatic environment. [ABSTRACT FROM AUTHOR]

Sugarcane bagesse was utilised as a low-cost adsorbent for the removal of metal ions. The study was done at a temperature of 35°C, and the maximum adsorption capacities for Pb(II) and Cd(II) ions were 3.02 and 2.90 mg/g, respectively, for sugarcane bagasse. These results were determined using the following optimum conditions: initial metal ion concentration of 100 mg/dm3, adsorbent weight of 0.5 g, time of 30 min and pH of 6. The adsorption of the metal ions by the adsorbents decreased with an increase in the initial concentration of the metal ions in an aqueous solution. The rate of adsorption also increased with temperature. The adsorption showed a good fit to the Langmuir model compared to the Freundlich adsorption model. The Langmuir dimensionless constant (RL) for the adsorption of Pb(II) ion and Cd(II) ion ranged from 0.081 to 0.123 and 0.115 to 0.172, respectively, which confirms favourable adsorption. The adsorption process showed that the pseudo-second-order kinetics was a better fit than the pseudo-first-order kinetics. The result of this work showed a low-cost and efficient potential of sugarcane bagasse to be employed as a good adsorbent for metal ion removal. [ABSTRACT FROM AUTHOR]

Nickel contamination in water is a critical issue due to its toxicity and persistence. This study presents a novel magnetic resin, developed by modifying Lewatit® MonoPlus TP 207 with magnetite nanoparticles, to enhance adsorption capacity and facilitate efficient separation. A Definitive Screening Design (DSD) was employed to identify and optimize key parameters affecting nickel adsorption, including pH, resin dosage, initial nickel concentration, and the presence of competing ions (calcium and magnesium). The DSD analysis revealed that pH and magnesium concentration were the most significant factors influencing nickel removal. Optimal conditions were determined as pH 7, 270 min contact time, resin dosage of 0.5 mL/L, initial nickel concentration of 110 µg/L, calcium concentration of 275 mg/L, and magnesium concentration of 52.5 mg/L, achieving a maximum removal efficiency of 99.21%. The magnetic resin exhibited enhanced adsorption capacity and faster kinetics compared to the unmodified resin, leading to more efficient nickel removal. Moreover, its magnetic properties facilitated rapid separation from treated water, offering practical advantages for real-world applications. This study demonstrates the effective use of DSD in optimizing adsorption parameters and underscores the potential of magnetic resin as a sustainable and efficient adsorbent for water treatment. [ABSTRACT FROM AUTHOR]

Termination kinetics of radical polymerization of N‐vinyl formamide (NVF) in aqueous solution has been measured via SP–PLP–NIR, i.e., single pulse (SP) initiation of pulsed laser polymerization (PLP) in conjunction with microsecond time‐resolved near‐infrared (NIR) detection of monomer concentration. Experiments are performed at initial NVF weight fractions from 0.20 up to bulk NVF, at monomer conversions up to 40%, and at temperatures from 40 to 70 °C as well as pressures from 500 to 2500 bar. Applying high pressure improves signal‐to‐noise quality. Data obtained upon pressure variation allow for extrapolation toward ambient pressure. The primary quantity from SP–PLP–NIR is kp/<kt>, i.e., the ratio of propagation rate coefficient, kp, to apparent chain‐length‐averaged termination rate coefficient, <kt>. With kp being available from literature, kp/<kt> yields <kt>. This quantity is relevant for modeling polymerization rate and polymer properties. Termination in the initial polymerization period turns out to be controlled by segmental diffusion and, at higher degrees of monomer conversion up to 40%, by translational diffusion. [ABSTRACT FROM AUTHOR]

Sodium chlorate is the most popular compound used to study spontaneous symmetry breaking by means of crystallization. Therefore, it is important to know the behavior of the solid particles. NaClO3 crystal growth and dissolution are investigated in an aqueous sessile droplet subjected to numerous temperature cycles. On cooling, in addition to the classical formation of repeated elongated fluid inclusions, there is a reproducible appearance of prismatic fluid inclusions (PFIs) at the corners of single crystals. The underlying mechanism involves the complete termination of the (110) face growth and the propagation of the {100} faces, which can close the PFIs. This study reports that on heating, transient donut-like single crystals formed, which could lead to their segmentation, even without stirring the suspension. The systematic addition of other sodium salts with chlorine atoms at different oxidation states did not change these observations. [ABSTRACT FROM AUTHOR]

Accurate determination of sodium chloride (NaCl) density in water is vital for assessing environmental impact, preventing soil salinization in agriculture, ensuring quality and consistency in industrial processes, facilitating medical treatments, and maintaining taste and preservation standards in the food and beverage industry. This paper introduces a novel microwave sensor design specifically tailored to accurately assess NaCl density in aqueous solutions. Starting with a standard solution of 10 g of salt dissolved in 100 ml of water, resulting in a molarity of approximately 1.71 M, five distinct samples are meticulously prepared. These samples cover a range of NaCl concentrations, with different ratios of salt solution and drinking water, including pure water, 10 ml of salt solution with 90 ml of water, 20 ml of salt solution with 80 ml of water, 30 ml of salt solution with 70 ml of water, and 40 ml of salt solution with 60 ml of water. Each sample undergoes analysis using the developed microwave sensor to determine its transmission coefficient. The magnitude of the transmission coefficient is closely tied to the density of the salt solution based on molarity. Through a detailed regression analysis, a strong quantitative relationship between the transmission coefficient and salt solution density is revealed. This correlation can be accurately represented by a third-order polynomial equation. This research is significant as it advances microwave sensor technology, allowing for accurate and efficient measurement of NaCl density in water. [ABSTRACT FROM AUTHOR]

The overuse of antibiotics and antitumor drugs has resulted in more and more extensive pollution of water bodies with organic drugs, causing detrimental ecological effects, which have attracted attention towards effective and sustainable methods for antibiotics and antitumor drug degradation. Here, the hybrid nanomaterial (g-C 3 N 4 @Fe/Pd) was synthesized and used to remove a kind of both an antibiotic and antitumor drug named mitoxantrone (MTX) with 92.0% removal efficiency, and the MTX removal capacity is 450 mg/g. After exposing to the hybrid material the MTX aqueous solution changed color from dark blue to lighter progressively, and LC-UV results of residual solutions show that a new peak at 3.0 min (MTX: 13.2 min) after removal by g-C 3 N 4 @Fe/Pd appears, with the simultaneous detection of intermediate products indicating that g-C 3 N 4 @Fe/Pd indeed degrades MTX. Detailed mass spectrometric analysis suggests that the nuclear mass ratio decreased from 445.2 (M+1H) to 126.0 (M+1H), 169.1 (M+1H), 239.2 (M+1H), 267.3 (M+1H), 285.2 (M+1H), 371.4 (M+1H) and 415.2 (M+1H), and the maximum proportion (5.63%) substance of all degradation products (126.0 (M+1H)) is 40-100 times less toxic than MTX. A mechanism for the removal and degradation of mitoxantrone was proposed. Besides, actual water experiments confirmed that the maximum removal capacity of MTX by g-C 3 N 4 @Fe/Pd is up to 492.4 mg/g (0.02 g/L, 10 ppm). [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pharmaceutically active compounds are the most widely produced and consumed consumer products that pose a substantial threat to the environment and living organisms owing to their pharmacokinetics, side effects, and contraindications. In this study, the degradation of chloroquine (CQ), a popular antimalarial and recently proposed COVID-19 drug, was investigated under electron beam (EB) irradiation of aqueous solutions. Both the hydroxyl radical and hydrated electron generated in the radiolysis of water contribute to the degradation of CQ in aqueous solution. The overall removal efficiency for 125 mg·L-1 of the CQ solution under EB treatment is reported to be >80% at neutral pH at a maximum irradiation dose of 7 kGy. Removal efficiency is further favored by acidic and slightly alkaline conditions where reactions with hydroxyl radicals and hydrated electrons are favored, respectively. Additionally, increments in the applied dose resulted in the increased removal efficiency for the same concentration of CQ. Conversely, the removal efficiency decreased with increasing concentration of CQ at the same irradiation dose. The initial solution pH, applied irradiation dose, and initial pollutant concentration play an important role in the EB-induced degradation of CQ by influencing the available oxidizing and reducing species. The chemical oxygen demand (COD) and total organic carbon (TOC) were not significantly decreased during the treatment process and indicated the formation of organic byproducts, which were not further degraded under the current experimental conditions.

Introduction: Nowadays, the management of drug effluents, as emerging pollutants, has attracted great attention due to human health and ecological adverse effects. During the COVID-19 pandemic, two drugs, Fexofenadine and Montelukast, have been used in large quantities for patients with lung involvement. The aim of this study is to investigate the feasibility of removing Fexofenadine and Montelukast and determine the removal kinetics. Material and Methods: In this study, we used Rhodotron accelerator to determine kinetic coefficients for the removal of drugs. Our research focused on studying the kinetics of E-Beam radiation reactions and the generation of significant amounts of free radicals during these processes. We employed first-order and second-order kinetic models under laboratory conditions, taking into account various influencing factors to establish the rate of removal. Results: The results showed that the decomposition of Fexofenadine and Montelukast drugs by high-energy E-Beam bending process is a pseudo-first-order reaction with a coefficient of more than 0.9105 and 0.998, respectively. The results showed that the reaction rate constant depended significantly on the initial concentration of Fexofenadine and Montelukast drugs and their molecular structure. Conclusion: Using a Rhodotron accelerator is important for removing Fexofenadine and Montelukast from the aquatic environment.

Receptors for carboxylate anions have many possible biomedical applications, including mimicry of the vancomycin group of antibiotics. However, binding carboxylates in water, the biological solvent, is highly challenging due to the hydrophilicity of these polar anions. Here we report, for the first time, the recognition of simple carboxylates such as acetate and formate in water by synthetic receptors with charge‐neutral binding sites. The receptors are solubilised by polyanionic side‐chains which, remarkably, do not preclude anion binding. The tricyclic structures feature two identical binding sites linked by polyaromatic bridges, capable of folding into closed, twisted conformations. This folding is hypothesised to preorganise the structures for anion recognition, mimicking the process which generates many protein binding sites. The architecture is suitable for elaboration into enclosed structures with potential for selective recognition of biologically relevant carboxylates. [ABSTRACT FROM AUTHOR]

Potentially poisonous elements (PPEs) water pollution has become one of the key issues in the field of water treatment. In recent years, it has threatened ecosystems as well as human health. This study aims to remove PPEs such as chromium (Cr6+), copper (Cu2+), lead (Pb2+), and Zinc (Zn2+) from both vehicle wash wastewater and aqueous solutions through batch experiments utilising carbonaceous adsorbents. Carbonaceous adsorbents were prepared from waste polyethylene terephthalate (wPET) and waste polystyrene (wPS) by carbonisation under a N2 atmosphere followed by chemical activation with 1 M KOH and 1 M HCl. The carbonaceous adsorbents were characterised by Fourier transform infrared spectroscopy, surface area analysis, as well as scanning electron microscopy. The results show that, except for Cr6+, the adsorption of PPEs from aqueous solutions is highly dependent on pH, and the highest removal rate was recorded at pH 6.0. However, the largest Cr6+ adsorption was noted at pH 3.0. Using 0.2 g of adsorbent, the adsorption reached equilibrium after 90 min. Results demonstrated that highest removal of Pb2+, Cu2+, Cr6+, and Zn2+ from aqueous solution achieved over wPET-AC adsorbent was 98.40%, 97.60%, 96.80% and 99.90%, respectively, whereas that of wPS-AC adsorbent was 96.30%, 95.64%, 94.22% and 97.60%, respectively. Root mean square error (RMSE) was also calculated for the validation of data. Isotherms as well as kinetics models are used to evaluate the adsorption capacity of carbonaceous adsorbents for PPEs. The experimental results have shown that the pseudo-second-order as well as Langmuir models are the most suitable for the data. Thermodynamic studies have shown that the adsorption of PPEs is spontaneous as well as endothermic in nature. This study shows that the novel carbonaceous adsorbent wPET-AC and wPS-AC has great potential to remove PPEs from vehicle wash wastewater. [ABSTRACT FROM AUTHOR]

Potentiometry and calorimetry are used to study Ce3+–glycine–ethylenediaminedisuccinic acid and La3+–glycine–ethylenediaminedisuccinic acid systems in aqueous solutions at T = 298.15 K (KNO3). The formation of a mixed-ligand complex is revealed, and the thermodynamic characteristics (ΔrH, ΔrG, ΔrS) of the complexation reaction are determined. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A predictive approach to the phase behavior of four-component polymer–water–surfactant–electrolyte systems is formulated by viewing the four-component system as a binary polymer–pseudosolvent system, with the pseudosolvent representing water, surfactant, and the electrolyte. The phase stability of this binary system is examined using the framework of the lattice fluid model of Sanchez and Lacombe. In the lattice fluid model, a pure component is represented by three equation-of-state parameters: the hard-core volume of a lattice site ( v * ), the number of lattice sites occupied by the component (r), and its characteristic energy ( ε * ). We introduce the extra-thermodynamic postulate that r and v * for the pseudosolvent are the same as for water and all surfactant–electrolyte composition-dependent characteristics of the pseudosolvent can be represented solely through its characteristic energy parameter. The key implication of the postulate is that the phase behavior of polymer–pseudosolvent systems will be identical for all pseudosolvents with equal values of characteristic energy, despite their varying real compositions. Based on the pseudosolvent model, illustrative phase diagrams have been computed for several four-component systems containing alkyl sulfonate/sulfate surfactants, electrolytes, and anionic or nonionic polymers. The pseudosolvent model is shown to describe all important trends in experimentally observed phase behavior pertaining to polymer and surfactant molecular characteristics. Most importantly, the pseudosolvent model allows one to construct a priori phase diagrams for any polymer–surfactant–electrolyte system, knowing just one experimental composition data for a system at the phase boundary, using available thermodynamic data on surfactants and electrolytes and without requiring any information on the polymer. [ABSTRACT FROM AUTHOR]

In view of the corrosion of steel strusture surface and its supporting strusture in an ambient water solution, the crack corrosion experiment, soaking experiment and electrochemical experiment of low alloy steel have been studied in the simulated aqueous solution. The corrosion morphology, corrosion product composition and electrochemical parameters of low alloy steel seamlss sample and crack sample in simulated aqueous solution have been analyzed. The results show that the corrosion of low alloy steel is mainly electrochemical reaction in the simulated aqueous solution. The initial corrosion products of rust layer are Fe(OH)3 and FeOOH products while the corrosion products in middle and later period are Fe3O4. The corrosion of crack sample is weaker than that of seamless sample, and the corrosion in the crack is much weaker than the corrosion outside the crack. Therefore, low alloy steel is not sensitive to crack corrosion in the simulated aqueous solution. [ABSTRACT FROM AUTHOR]

Octa-acid 1 is a water-soluble cavitand that has been used to investigate hydrophobic solvation and Hofmeister effects, control photophysical and physicochemical properties, modulate the reactivity of encapsulated guests, and as a tool to engender novel separation protocols. The synthesis of 1 has largely centered around its formation from 2, a host that is itself most readily synthesized on the multi-gram-scale in crude form (>75% purity). In this Methods Article we reveal improvements in the synthesis of 2, as well as a new synthetic strategy that efficiently converts crude 2 into pure 1. This provides access to 1 in only a five-step linear sequence, shortening the total reaction time from previous methods, improving the purity, and increasing the final yield of 1. We therefore anticipate that the described protocols will be of interest to researchers seeking to utilize octa-acid in their studies. [ABSTRACT FROM AUTHOR]

The present work is an attempt to address the feasibility of sewage sludge as a cost-effective adsorbent for the Congo Red (CR) elimination from a wastewater sample. The physicochemical properties of treated sewage sludge SS40 were identified by using several techniques, such as Thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), zeta potential, and Fourier transform infrared spectroscopy (FTIR), Furthermore, to describe the adsorption balance, the experimental results were analyzed using the Langmuir, Freundlich, and Sips isotherms. The equilibrium was perfectly described by the Langmuir model, and the peak adsorption capacity in the monolayer was 25.10 mg. g−1 at 40 °C. The kinetic data of adsorption were analyzed by the Pseudo-First Order (PFO), Pseudo-Second Order (PSO), and Elovich models. The results indicated that both Elovich and PSO models were the most appropriate for describing the adsorption of CR onto (SS40) for all initial CR concentrations, indicating that the chemisorption controlled the dye retention by SS40. The determination of thermodynamic parameters showed that ΔG0 was − 9.42 kJ.mol−1 at 40 °C, ΔH0 was 10.64 kJ.mol−1, and ΔS0 was 30.14 J.mol−1. K−1. The adsorption of CR on SS40 was found to be feasible, spontaneous, and endothermic. The results of this study demonstrate that sewage sludge from the domestic wastewater treatment plant can be used advantageously as an economical, easy-to-handle, and eco-friendly sorbent for the elimination of CR as an emerging pollutant from aqueous solutions. [ABSTRACT FROM AUTHOR]

This research provides valuable insights into using raw sugarcane bagasse (SB) as an adsorbent for dye removal from wastewater. Various activation and modification methods for SB were explored, including physical, chemical, and biological treatments, as well as composite formation and grafting. The study examined the effects of different optimization conditions on the adsorption process, such as adsorbent dosage, initial dye concentration, pH, and contact time. Key findings include an equilibrium contact time of 30 minutes for methylene blue dye, resulting in an 86% removal rate. The optimal pH for dye removal was identified as pH 6, achieving an 84% removal rate. The study also found that the optimum dye concentration for removal was 10 ppm, with a 70% removal rate, and the optimal adsorbent dosage was 0.4g, resulting in an 81% removal rate. These results demonstrate the effectiveness of raw sugarcane bagasse in adsorbing methylene blue dye under specific conditions, highlighting its potential as a low-cost and efficient adsorbent for wastewater treatment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University / Dongnan Daxue Xuebao is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic surroundings. Recently reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots (CNDs) is still a challenging issue. Herein, full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement, and Förster energy resonance transfer is used for further tuning phosphorescence range. The phosphorescence spans across most of the visible spectrum, ranging from 400 to 700 nm. In an aqueous solution, the CNDs exhibits blue, green, and red phosphorescence, lasting for approximately 6, 10, and 7 s, respectively. Correspondingly, the phosphorescence quantum yields are 11.85%, 8.6% and 3.56%, making them readily discernible to the naked eyes and laying a solid foundation for practical application. Furthermore, phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials, showing distinct superiority for accuracy and complete display and imaging in complex emission background. [ABSTRACT FROM AUTHOR]

Nowadays, water pollution by herbicides is known as a global concern. Paraquat (PQ) (1-1-methyl-4,4-bi-pyridinium-dichloride) is a chip with high performance, which is being widely used herbicide to remove weeds from agricultural and natural ecosystems. PQ can contaminate water sources due to its high solubility in water. Human death by poisoning effects of PQ has been reported in several countries. Therefore, the side effects of PQ are a global challenge. This study aimed to investigate the bioremediation of PQ by plant extracts, as a low-cost, nontoxic, and natural absorbent to remove PQ from aqueous solutions in different conditions. In this regard, the extracts of common purslane (portulaca oleracea), florist kalanchoe (kalanchoe blossfeldiana), and jade plant (crassula portulaca) were used as adsorbents. For this purpose, the effect of various parameters such as contact time, initial concentration of PQ solution, temperature, pH, and amount of extract was investigated. The results of present study showed that P. oleracea extract and C. portulaca extracts have higher adsorption efficiency than k. blossfeldiana extract. The highest PQ removal was obtained by P. oleracea extract (79.04%) and C. portulaca extract (78.72%) at pH = 11, the adsorbent content of 0.2 mg L−1, and the lowest absorption of PQ (50.6%) was obtained by K. blossfeldiana extract. The highest PQ removal by plant extract was observed at 30 min for P. oleracea and C. portulaca, and at 15 min for k. blossfeldiana extract. Moreover, surface absorption capacity increased with increasing plant extract concentration, decreasing PQ concentration and decreased with increasing temperature. Finally, it can be concluded that plant extract can help to remove PQ from the aqueous solution. Contamination of raw water with herbicides such as paraquat (PQ) is recognized as a problem in many countries. PQ is known as a chemical contaminant that is highly toxic with high water solubilities (620 g/l) among herbicides. Despite the ban on the use of PQ in some countries, due to its low price, high efficiency at low concentrations, and high speed of paraquat in suppressing weeds, today this herbicide is used to control a wide range of weeds in the world. In recent years, various approaches to removing PQ from the environment have been studied. Some of these methods are relatively time-consuming and expensive, with large amounts of sludge and hazardous by-products. Among the mentioned methods, the adsorption process shows the simplicity of operation, low-cost process, and high efficiency in removing PQ from water. Recently, many adsorbents have been developed to remove PQ from aqueous solutions, including biochar, activated carbon, chitosan and alginate, clay, rice husk, and bentonite. Plant extracts may be known as new adsorbent materials for removing PQ from water as an eco-friendly and economical process. Therefore, in this study we investigate the plant extracts performance as adsorbents in PQ removal from water. [ABSTRACT FROM AUTHOR]

Pharmaceutical pollutants are among the most important issues in human life. The reason for investigating and controlling environmental pollution is the entry of these pollutants into the food cycle and drug resistance, which causes many environmental risks. In this study, the rate of photocatalytic degradation of TMP, a model organic pollutant, was investigated using NiFe2O4@MoO3 nanocomposites. The characteristics of the nanocomposites were identified using XRD, FESEM, EDX, and VSM techniques. This study aimed to explore the effects of different factors on the photocatalytic removal of the trimethoprim antibiotic (TMP) using a central composite design (CCD) and response surface method (RSM). Significant variables were identified, including initial pH (3–9), catalyst dose (5–100 mg/L), pollutant concentration (20–100 mg/L), and contact time (0–120 min), and 30 experiments were conducted to optimize the process. Statistical analysis based on analysis of variance (ANOVA) showed that the following factors influenced the response. In addition, the results showed that the efficiency of the photocatalytic process increased with an increase in catalyst and residence time, and the efficiency of the photocatalytic process increased with an increase in pH up to 6.3. RSM results revealed the best experimental conditions for TMP degradation under UV light. They showed that the initial pollutant concentration and pH had a greater impact on the degradation process than did the catalyst dose and retention time. This suggests that optimizing operational factors can significantly improve the performance of photocatalytic processes for removing antibiotics such as trimethoprim. [ABSTRACT FROM AUTHOR]

Photoemissions from aqueous solutions are prone to elastic and inelastic electron scattering, streaming potential, and space charge effect errors; however, direct assessments of their individual contributions are still a daunting challenge. Herein, to assess how these errors in a combined experimental error manner influence on the genuine photoelectron kinetic energy (PKE) spectra, the ultraviolet PKE (or electron binding energy, eBE) spectra of aqueous thymidine at different solution flow rates and laser energies were investigated by femtosecond liquid-microjet photoelectron spectroscopy. The accurate vertical eBE value of 11.33 eV for the lbi orbital of liquid water was used to calibrate the observed eBE spectra of aqueous thymidine, and the corresponding combined experimental error for the eBE of the lbi orbital of liquid water was estimated to be about 200 meV. The average combined experimental error for the vertical eBE values of the cationic ground state D0(π−1) and the cationic first excited state D1(n-−1) of aqueous thymidine was estimated to be less than 3%, i.e., in the range of several tens of meV to 200 meV, depending on different flow rates and laser energies. [ABSTRACT FROM AUTHOR]

Eosin dye is an efficient qualitative and quantitative chemical through various scientific and biological uses but it was demonstrated as a lethal substance to animal or human lung, liver, eye, kidney, Central Nerve System (CNS) and parts of gastrointestinal system. In many published studies, it removed via clay/carbon composite, lemon peel, or fly ash adsorption beside oxidation, filtration, photocatalysis, ion exchange, sonochemistry, nanotechnology, and others. Here, is another attempt to prepare an activated carbon from carbon-based material (low quality face tissue) where its capacity was determined by toxic anionic dye (Eosin B) – spectroscopic investigation. In this attempt, Eosin B showed an excellent removal and adsorption capacity starting from first 5 mL eluted from this prepared adsorbent. Removal of Eosin is important to human and environment where present In Silico study confirmed that Eosin B was safe to embryo or foetus health (during pregnancy) , Cardio- topic including: Arrhythmia, Cardiac Failure, Heart Block, hERG Toxicity, Hypertension, and Myocardial Infarction, toxic to avian with high Rat Acute Toxicity (LD50) lowest probability of lung, prostate, and renal cell lines even with its water solubility in aqua environment, Yes response towards P-glycoprotein substrate or multidrug resistance (MDR1) function in cancer pharmacotherapy. Also, Eosin B had BBB or CNS permeability as well as fish (Minnow) toxicity. It is safe for Renal OCT2 substrate, besides hERG I & II inhibitors, Hepatotoxicity, and skin sensitization, Cytochromes P450 under testing. Therefore, Eosin B is structurally toxic to human and environment in short – or long – term period.

In this work, a laboratory examination of the effectiveness of the metal–organic framework ZIF-67 for the elimination of arsenate from aqueous media was evaluated. The properties of the adsorbent were specified by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FTIR) methods. The impact of various factors like a temperature (25–65 °C), elimination time (5–85 min), pH (2–10), initial content of arsenic (2–10 mg/L), and adsorbent content (0.1–0.9 g/L) was checked. Central Composite Design (CCD) model was utilized to optimize the process. This study showed that the optimal conditions for arsenic elimination are pH level = 6, contact time = 55 min, temperature degree = 47 °C, adsorbent content = 0.58 g/L, and initial content = 5 mg/L. The highest uptake capacity of arsenate was 62.98 mg/g, The experimental findings indicated that the uptake isotherm adheres to the Langmuir model, with an R2 level of 0.99. Additionally, the kinetic studies were successfully modeled using a pseudo-second-order approach, achieving an R2 = 1. Overall, this study illustrates that the efficiency of the metal–organic framework ZIF-67 in eliminating arsenate from aqueous solutions is promising.

The exploration of efficient lead-free perovskite photoelectric active materials to develop high-performance photoelectrochemical (PEC) systems in aqueous solution is crucial to expand their PEC applications. Herein, we successfully constructed a high-performance PEC platform using ligand-free perovskite Cs2PdBr6 microcrystals (MCs) as the photoactive substance. The Cs2PdBr6 MCs showed narrow bandgap, wide absorption range, high electronic mobility and good stability in aqueous solutions. Particularly, the Cs2PdBr6 MCs exhibited an excellent photoresponse, the photocurrent density could reach as high as 98 μA/cm2 under 10.18 mW/cm2 light irradiation in the absence of other electron acceptors. In addition of the extremely wide range of response wavelength, wide pH range and accelerated interfacial carrier transfer, the Cs2PdBr6 MCs demonstrated the significant potential of photocathode active material for applications in PEC sensors and optoelectronic devices. Therefore, this work indicates that Cs2PdBr6 MCs design is a highly efficient way to solve the intrinsic issues of perovskite material, predicting a promising strategy for high performance PEC application in aqueous ambience.

In this study, graphene oxide (GO) adsorbent was prepared by modified Hummer’s method and functionalized with aminomethylphosphonic acid. Its application to the adsorption of Sr ions from aqueous solutions in a batch sorption process was investigated. Adsorbents were characterized by TEM and FT-IR. The TEM images of functionalized graphene oxide showed that graphene sheets are formed in wavy sheets. The FTIR spectrum revealed that graphene oxide was highly functionalized with aminomethylphosphonic acid and oxygenated functional groups were reduced. Response surface methodology investigates pH, adsorbent dosage, and temperature parameters. The quadratic model corresponds well with the experimental data. The results illustrated that there is no systematic error in the experiments. The verification of the model with random experiments showed a low error in the values predicted by the model. The kinetic data were analyzed by Pseudo-first-order, Pseudo-second-order, and Double- exponential kinetic models, and experimental data were well modeled by the pseudo-second-order kinetic model. The research results showed that graphene oxide functionalized with aminomethylphosphonic acid has a good ability to strontium adsorption from aqueous solutions.

AbstractAtomistic molecular dynamics simulations of the single chains of cationic polyelectrolytes of atactic poly(vinyl amines) (PVAm) modified by hydrophobic side-groups, poly(N-ethyl-n-vinyl amine) (ethyl-PVAm) and poly(N-benzyl-n-vinyl amine) (benzyl-PVAm), in aqueous solution, were carried out over the entire range of degree-of-ionization, f. These polymers, to our knowledge, were studied here by molecular simulations for the first time. The interplay of electrostatic interactions, excluded volume, hydrophobic effect, hydrogen bonding and counter-ion interaction with hydrophobic-polyions, is analyzed. The conformational transition of the polyelectrolyte chain from a coiled to an extended state was gradual and was observed for 0.3 < f < 0.7. Ethyl-PVAm and benzyl-PVAm exhibited similar values of radius-of-gyration Rg and end-to-end distance R for f > 0.5, in agreement with available experimental data. The more hydrophobic benzyl-PVAm showed a more extended conformation with a preference for trans states in the backbone. The change in chain expansion with respect to f was more for benzyl-PVAm as compared to ethyl-PVAm. The relaxation time of polymer-water H-bonds increased with f and the hydrophobicity of the polymer chain, with faster decay for ethyl-PVAm. The water molecules solvating the hydrophobic PVAm’s showed dynamical restriction due to bulky hydrophobic side-groups resulting in long-lived H-bonds. The number of polymer-water H-bonds showed a transition at a certain charge, which influenced the complex interplay of steric effect, hydrophobic effect and solvation. [ABSTRACT FROM AUTHOR]

Carbonaceous materials produced from agricultural waste (palm kernel shell) by pyrolysis can be a proper type of low-cost adsorbent for wide uses in radioactive effluent treatment. In this context, the as-produced bio-char (labeled as PBC) and its sub-driven sulfuric acid and zinc oxide activated carbons (labeled as PBC-SA, and PBC-Zn respectively) were employed as adsorbents for uranium sorption from aqueous solution. Various analytical techniques, including SEM (Scanning Electron Microscopy), EXD (X-ray Diffraction), BET (Brunauer–Emmett–Teller), FTIR (Fourier Transform Infrared Spectroscopy), and Zeta potential, provide insights into the material characteristics. Kinetic and isotherm investigations illuminated that the sorption process using the three sorbents is nicely fitted with Pseudo-second-order-kinetic and Langmuir isotherm models. The picked data display that the equilibrium time was 60 min, and the maximum sorption capacity was 9.89, 16.8, and 21.9 mg/g for PBC, PBC-SA, and PBC-Zn respectively, which reflects the highest affinity for zinc oxide, activated bio-char, among the three adsorbents, for uranium taking out from radioactive wastewater. Sorption thermodynamics declare that the sorption of U(VI) is an exothermic, spontaneous, and feasible process. About 92% of the uranium-loaded PBC-Zn sorbent was eluted using 1.0 M CH3COONa sodium ethanoate solution, and the sorbent demonstrated proper stability for 5 consecutive sorption/desorption cycles. [ABSTRACT FROM AUTHOR]

The purpose of this study was to remove Cr(III) ions from aqueous solution using biochar@Fe3O4@SDS nanocomposite. Biochar@Fe3O4@SDS was synthesized as a novel adsorbent by chemical co-precipitation method. The structural features of the nanocomposite were investigated using energy-dispersive spectroscopy (EDS), dynamic light scattering (DLS), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. The BET surface area and the mean pore diameter of the biochar@Fe3O4@SDS were 102.04 m2/g and 169.49°A, respectively, indicating the high porosity of the aforementioned nanocomposite. DLS and XRD analyses showed that the mean particle size and crystal size of biochar@Fe3O4@SDS are 78.9 nm and 28 nm, respectively. Also, the highest Cr(III) removal efficiency (99.5%) using biochar@Fe3O4@SDS was obtained at pH = 9, contact time = 40 min, temperature = 55 ºC, the Cr(III) ion concentration = 10 mg/L, and the nanocomposite dosage = 2 g/L. Moreover, the maximum sorption capacity obtained from the Langmuir model was 120.48 mg/g, which is a significant value compared to previous studies for Cr(III) removal. Furthermore, the isotherm study indicated that the Cr(III) sorption process using the aforementioned nanocomposite followed the Freundlich models due to the higher correlation coefficient (0.986). Also, the pseudo-second order kinetic model with a correlation coefficient of 1 was better fitted than the pseudo-first order model with experimental data. Subsequently, the thermodynamic study demonstrated that the sorption process of Cr(III) ions using biochar@Fe3O4@SDS is favorable, feasible, spontaneous, and endothermic. [ABSTRACT FROM AUTHOR]

In this study, we used an improved "diffusion cell" method to precisely determine the diffusion-driven kinetic isotope fractionation factors of the Li, K, Rb, Mg, Ca, Sr, and Ba cations in aqueous solutions under room temperature. The obtained isotope fractionation factors (±2σ errors) are, α 7/6Li = 0.996139 ± 0.000140, α 41/39K = 0.998572 ± 0.000072, α 87/85Rb = 0.999333 ± 0.000020, α 26/24Mg = 0.999877 ± 0.000010, α 44/42Ca = 0.999704 ± 0.000010, α 88/86Sr = 0.999781 ± 0.000014, α 138/135Ba = 0.999716 ± 0.000018. The results show that the charge of the cation and the ion-water bond length for the aquo ions are the two predominant factors affecting the mass dependence of isotope fractionation (β factor) during cation diffusion in aqueous solutions. Cations with higher charge numbers and shorter ion-water bond lengths exhibit less kinetic isotope fractionation during diffusion. Therefore, the isotope separation effect during diffusion (or β factor) in fluids is fundamentally controlled by the intensity of ion-water interaction. Weaker ion-water interaction (e.g., lower charge number, longer ion-water bond length) leads to less prominent hydrodynamic behavior for diffusing ions at the molecular level, thus more significant isotope fractionation in bulk solutions, and vice versa. Ions of larger radius would show stronger mass dependence of isotope fractionation (β factor), which can cancel the effect of decreasing relative isotope mass difference for heavier elements, thus kinetic isotope fractionation during diffusion in aqueous solutions remains prominent even for heavy elements such as Rb, Sr, and Ba. The diffusion-driven kinetic isotope fractionation factors measured in this study could provide a useful basis for interpreting specific natural isotopic variability of alkaline and alkaline-earth elements in supergene environments where chemical diffusion takes place. [ABSTRACT FROM AUTHOR]

In the present study the behavior of Cu(II) and Zn(II) complexes with ethylenediamine and 2,2′:6′,2′′ terpyridine in an aqueous environment was studied by classical MD simulations. Special attention was paid to the effect of Cu2+ for Zn2+ substitution on complex water surroundings and mobility. The replacement of a metal ion affects the structure of the complex water environment only in the vicinity of its location. However, it changes such a characteristic as the lifetime of a water molecule in the first coordination shell of a metal which can significantly affect the mobility of the complex. Moreover, the degree of influence on translational and rotational mobility can be different. [ABSTRACT FROM AUTHOR]

Structural and mechanical testing results obtained for carbon fiber-reinforced plastics made of carbon tape coated with stainless steel based on an epoxy binder are presented. The carbon fiber-reinforced plastic samples were produced based on an infusion technology with the use of various curing techniques. The finished samples were kept in a 7% NaCI solution, with assessing the interlayer shear strength and microstructure thereof. Based on these studies, it has been revealed that the use of a modified vacuum infusion technology provides obtaining high quality carbon fiber-reinforced plastics. [ABSTRACT FROM AUTHOR]

In the work using the quantum-chemical modeling method, the possibility of binding orthosilicate acid with different amounts of methanesulfonate anions was considered. It was demonstrated that methanesulfonic acid forms two hydrogen bonds with a molecule of orthosilicate acid, regardless of the conformation of the cluster itself. According to the results of calculations of energy parameters of systems and frontier molecular orbitals, it was established that the most stable cluster of orthosilicate acid with methanesulfonate anion is [H4SiO4 · 4CH3SO3–]. It was also established that the formation of an eight-membered cycle (S–O···H–O–Si–O–H···O) and (S–O···H –O–Si–O···H–С). Furthermore, it was established that there is no significant dependence of the effective charge on the silicon atom on the number of methanesulfonate anions in the inner sphere. Thus, it is theoretically demonstrated that the methanesulfonate anion is able to stabilize orthosilicate acid and reduce the possibility of its dimerization.

Cationic porous organic polymers have a unique advantage in removing radioactive iodine from the aqueous phase because iodine molecules exist mainly in the form of iodine-containing anions. However, halogen anions will inevitably be released into water during the ion-exchange process. Herein, we reported a novel and easy-to-construct zwitterionic hypercrosslinked polymer (7AIn-PiP)-containing cationic pyridinium-type group, uncharged pyridine-type group, pyrrole-type group, and even an electron-rich phenyl group, which in synergy effectively removed 94.2% (456 nm) of I2 from saturated I2 aqueous solution within 30 min, surpassing many reported iodine adsorbents. Moreover, an I2 adsorption efficiency of ~95% can still be achieved after three cyclic evaluations, indicating a good recycling performance. More importantly, a unique dual 1,3-dipole was obtained and characterized by 1H/13C NMR, HRMS, and FTIR, correlating with the structure of 7AIn-PiP. In addition, the analysis of adsorption kinetics and the characterization of I2@7AIn-PiP indicate that the multiple binding sites simultaneously contribute to the high affinity towards iodine species by both physisorption and chemisorption. Furthermore, an interesting phenomenon of inducing the formation of HIO2 in unsaturated I2 aqueous solution was discovered and explained. Overall, this work is of great significance for both material and radiation protection science.

This work is a development and extension of the previous one (DOI: 10.1039/d3cp00882g). Here, H‐dimers of acridine (acridine orange—AO and proflavine—PF), thiazine (methylene blue—MB and thionine—TH), and oxazine (brilliant cresyl blue—BCB and Nile blue—NB) dyes were modeled using hybrid functionals with a large proportion of exact Hartree–Fock exchange and long‐range correction. It turned out that nine functionals (LC‐ωHPBE, M06HF, M052X, M062X, M08HX, M11, MN15, SOGGA11X, and ωB97XD) reliably stabilize these molecular aggregates in both the ground and excited states. In addition, these functionals ensure that the conditions for transition moments (M(dimer) ≈ 2$$ \sqrt{2} $$M(monomer) from strong coupling theory for H‐aggregates) and absorption maxima (λmax(dimer) < λmax(monomer) from Kasha exciton theory) are met. The S2 excited state stabilizes the H‐dimers more strongly than the ground state, while the S1 state stabilizes even more than S2. This is due to the large overlap between the corresponding molecular orbitals (LUMO > HOMO−1 > HOMO). When calculating the vibronic absorption spectra, the best agreement with the experiment for AO2, PF2, and NB2 showed the M08HX functional, and M11—for MB2 and BCB2. For dye monomers, these functionals gave the worst agreement, and MN15 demonstrated the closest similarity to the experiment. Vibronic absorption spectra for AO2, MB2, BCB2, and NB2 were calculated for the first time. The exciton splitting is calculated, which for MB2 is in good agreement with the experimental value. [ABSTRACT FROM AUTHOR]

The kinetic features of the degradation of ibuprofen (IBU) in its aqueous solution by the action of atmospheric-pressure dielectric-barrier discharge in an oxygen stream have been studied. The range of concentrations was (8.6–42.8) mg/L, and the range of power input to the discharge was (7–57) W. It has been found that the degradation process is formally described by the first-order rate equation in ibuprofen concentration. Degradation rates, effective degradation rate constants, and degrees of destruction have been determined. At a fixed discharge power, the constants do not depend on the initial concentration of the solution. Typical values of the rate constants are ~(0.2–0.7) s−1. Based on these data, energy yields and degrees of degradation at various discharge powers (discharge currents) have been calculated. The energy yields of degradation are in the range of (4–9) × 10−3 molecule per 100 eV of input energy, with the degree of degradation reaching 100%. It has been found that carboxylic acids and aldehydes are formed as a result of IBU degradation. [ABSTRACT FROM AUTHOR]

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