Chemical Papers最新文献

In this study, a nitrogen-doped multi-walled carbon nanotube (N-MWCNTs)/silver nanowire (AgNWs) nanocomposite electrode was prepared, using polydimethylsiloxane (PDMS) as a flexible substrate and N-MWCNTs and AgNWs as conductive materials. Trace Cu(II) in water was monitored by square wave stripping voltammetry (SWSV). Compared with commercial electrodes, the N-MWCNTs/AgNWs composite electrode generated much higher responsive peak current in detecting Cu(II), due to the enhanced conductivity of the composite electrode and the strong complexing ability of the N-MWCNTs for Cu(II). In the SWSV, this new electrode showed 0.06 μg/L (S/N = 3) limit of detection, a linear range from 0.500 to 100 μg/L, high resistance to interfering metals such as Ca(II), K(I), Zn(II), Na(I), Al(III), Fe(III), Hg(II), Cr(VI), Bi(III), Sb(III) and Sn(II), and stable response in natural water samples without sample pretreatment. This study established a new method for facile fabrication of high-performance flexible Cu(II) sensor with N-MWCNTs and AgNWs.

This study provides valuable insights into the structural and chemical characteristics of zinc oxide nanoparticles (ZnO NPs), enhancing their antimicrobial efficacy against Gram-positive bacteria and fungi. Structural and optical analyses of ZnO NPs synthesized via a green route revealed a floral morphology at 450 °C with petal sizes averaging ~ 20.56 nm. Size and strain characteristics were extensively investigated using mathematical techniques such as the Scherrer and Williamson–Hall methods. The influence of key parameters, including nanoparticle concentration and UV exposure, on the antimicrobial efficacy of UV-irradiated ZnO nanoparticles was examined. Biochemical assays suggest that the synthesized ZnO nanoparticles hold potential as novel antimicrobial agents for effectively controlling microbial infections. Notably, oxidative stress markers showed a significant increase in protein carbonyl formation in Staphylococcus aureus (31,237 nmol/mg) and Candida albicans (29,109 nmol/mg). Additionally, the time-dependent antimicrobial effect revealed reduction in microbial growth over specified periods, indicating prolonged antimicrobial activity. The molecular-level study demonstrates that the antimicrobial activity of ZnO NPs, particularly upon UV activation, is mediated through the production of ROS, leading to oxidative stress, protein damage, enzymatic activity disruption, and membrane integrity compromise, ultimately resulting in microbial cell death.

Textile production is estimated to be responsible for about 20% of global clean water pollution from dyeing and finishing products. Textile wastewater discharge is one of the most hazardous pollutants which has a strong possibility to be mixed with freshwater bodies making the clean water unfit for further utilization. Chemical oxygen demand (COD) and biological oxygen demand (BOD) are the important indicators that describe the pollution level of the water. Pretreatment of textiles using hazardous chemicals boosts the toxicity of water due to the release of chemicals from textile fibrous surfaces into clean drinking water polluting the aquatic environment. This research aimed to develop a correlation between COD and BOD concerning auxiliaries used in the conventional and bio-pretreatment of textiles, so that the wastewater load can be traced back to the pretreatment method applied in upstream procedures. Furthermore, a comparison was established between COD and BOD of conventional and enzymatic processes. At first, the desizing of gray fabric was done, followed by scouring and bleaching. Then, scouring and bleaching were performed by conventional and enzymatic methods to examine their association with the rise in COD and BOD levels of effluent. Results confirmed that auxiliaries used in traditional and bio-pretreatments of textiles are significantly responsible for wastewater load. However, COD and BOD values of effluent obtained after enzymatic pretreatments were substantially less compared to conventional pretreatment methods. Therefore, enzymatic pretreatment application in textile chemical processing will help reduce effluent pollution and promote sustainable practices (SDG 6) with less environmental impact.

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In this study, we investigated the polyphenolic composition of the n-butanol fraction of Linum trigynum L. (BELTr), a medicinal plant from the Linaceae family that grows in Algeria, using RP–UHPLC–ESI–QTOF–MS technique and evaluated of its antimicrobial, larvicidal and inhibition of α-amylase and butyrylcholinesterase (BChE) potentials. Fifty-six polyphenols were identified in the BELTr with isomers of vicenin-2 and orientin, and isovitexin as the major compounds. The extract showed a significant inhibition of BChE (IC₅₀: 112.45 ± 3.93 µg/mL) and a good inhibition of α-amylase (IC₅₀: 2.25 ± 4.05 mg/mL). In addition, the BFLTr exhibited antimicrobial activity against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 6538P, Salmonella enterica ATCC 13076, Bacillus subtilis ATCC 6633, Klebsiella pneumoniae ATCC 13883, Enterococcus faecalis ATCC 19433 and Pseudomonas aeruginosa ATCC 27853, as well as a yeast strain, Candida albicans ATCC 1031, with MICs values ranging between 250 and 500 µg/mL and a weak larvicidal effect. The extract’s activities may be attributed to its richness in flavonoids and phenolic acids, either through a direct mechanism or in a synergistic one.

The sorption of some essential ions by economical and effective methods is crucial in development and technology. The sorption of Cs(I), Co(II), and Ni(II) from aqueous solutions using carboxymethyl cellulose/clay (CMC/clay) sorbent synthesized by precipitation method was studied by batch technique. Different analytical tools like SEM, XRD, FTIR, DTA, and TGA analysis were utilized to find morphology, structure, functional groups, and thermal analysis for CMC/clay. The adsorption process was performed by changing different adsorption factors such as pH, shaking time, initial Cs(I), Co(II), and Ni(II) concentrations, and temperature to get maximum removal of the studied cations. The elements removal process followed pseudo-second-order with the values of regression factor (R²) found as 0.988, 0.995, and 0.996 for Cs(I), Co(II), and Ni(II), respectively. The equilibrium data fitted well to the Langmuir isotherm. The monolayer capacity values were found to be 25.9, 23.7, and 18.5 mg/g for Cs(I), Co(II), and Ni(II), respectively. The thermodynamic functions reflect an endothermic and spontaneous sorption process. Desorption of Cs(I), Co(II), and Ni(II) from the loaded CMC/clay was done using different eluents, and the best eluant was 0.5M of HCl. The data revealed that CMC/clay sorbent is suitable for recovering Cs(I), Co(II), and Ni(II) from aqueous solutions. The real sample application proved that CMC/clay is an excellent sorbent for the capture of Ni(II) from industrial wastewater.

A novel binding gel for the DGT technique, containing biochar produced through the pyrolysis of wheat bran, was developed. The results of this study indicate that wheat bran biochar (WBBC) is a porous material with a surface area of 25 m²/g. The primary functional group on the surface of WBBC was identified as a carbonyl group, although some hydroxyl and imino groups were also detected. Furthermore, the findings demonstrate that the accumulation of Hg on WBBC was significantly influenced by an increase in ionic strength, particularly in NaCl solution, owing to Hg’s high affinity for chloride ions. The performance of the DGT with WBBC binding gel was also affected by solution pH, with the optimal pH for WBBC application falling within the range of 3–7. The diffusion coefficient of Hg, depending on the matrix environment, varied between 5.44 and 6.99 × 10⁻⁶ cm²/s. When applying the newly designed DGT technique to spiked samples of river water, an R value of 0.68 was achieved. The results of this work proved that modified DGT technique allows for a cost-effective analysis of Hg in natural waters with lower salinity, while retaining the fundamental properties of the binding gel incorporating a particulate adsorbent with anchored functional groups.

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Our study aimed to examine the phytochemical composition and biological features of Cotula cinerea, an indigenous plant found in the Algerian Sahara. The aqueous maceration process was used to get the extract of Cotula cinerea, which showed a high concentration of polyphenols (34.01 ± 1.08 mg GAE/g) and flavonoids (24.10 ± 0.82 mg EQ/g). The toxicity studies on rats demonstrated no detrimental effects, confirming the extract’s safety. Notably, the use of C. cinerea extract showed significant results in lowering blood sugar levels. The diabetic rats that received the extract showed significantly reduced glucose levels (D500 = 1.04 ± 0.13 g/l) compared to those without treatment (2.92 ± 0.23 g/l). In addition, all other biochemical parameters in the diabetic rats who received treatment were comparable to or superior to those of the control group. The extract’s antioxidant capacity was verified through in vitro testing utilizing DPPH (IC₅₀ = 0.54 ± 0.023 mg/ml) and FRAP (IC₅₀ = 0.51 ± 0.012 mg/ml) tests. Ascorbic acid was used as a reference, with concentrations of 0.06 ± 0.005 mg/ml and 0.11 ± 0.014 mg/ml for the respective assays. Moreover, the plant's anti-inflammatory properties were assessed both in vitro and in vivo. Its effectiveness was ranked in the following order: The order of effectiveness, from highest to lowest, is as follows: Aspirin, Diclofenac, Extract (500 mg/kg b.w.), Extract (250 mg/kg b.w.). The findings emphasize the potential of C. cinerea as a promising reservoir of bioactive chemicals with notable hypoglycemic, antioxidant, and anti-inflammatory activities.

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In this study, the hydrolysis of TiCl₄ was utilized to synthesize titanium dioxide clusters (TiO₂ NCs) at a sub-nanometer scale. Precise control over the synthesis process resulted in the production of stable particles with well-defined size distributions. These TiO₂ NCs were specifically developed to facilitate the conversion of SO_x into organo-sulfonic acid derivatives under visible light irradiation. Various characterization techniques such as TEM, EDX, XRD, UV–Vis-DRS, Raman, and FTIR were employed to analyze the formed photocatalysts, including TiO₂ nanoparticles (NPs) and NCs. The efficiency of catalytic SO_x removal depended significantly on the particle size and surface area of the nanocatalysts, as well as the presence of thymol or naphthol (1,2). These materials (1,2) proved to be highly effective in removing SO_x from flue gas under ambient conditions, specifically at room temperature. The conversion of thymol or naphthol involved a combination of adsorption and catalytic oxidation–reduction reactions. This photocatalytic approach for SO_x conversion offers several advantages, including high performance, elimination of the need for high temperature or pressure, and rapid catalytic removal within a short reaction time of 10 min. TiO₂ NCs demonstrate high efficiency in SO_x removal, offering a promising solution for pollution control. Unlike some other methods, TiO₂ nanoparticles can be potentially regenerated and reused, making them a more sustainable approach.

This work described a plant extract-based synthesis of titanium oxide nanoparticles (D-TiO₂–NPs) using Duranta erecta leave extract, followed by the fabrication of its nanocomposite (D-TiO₂–NC) with chitosan for adsorptive removal of toxic metals (TMs) cadmium (Cd) and lead (Pb) from water. D-TiO₂–NPs and D-TiO₂–NC were characterized by various analytical techniques. This study confirmed the porous and rough crystalline nanostructure with different functional groups of chitosan and D-TiO₂–NPs of synthesized D-TiO₂–NC for feasible excellent adsorptive removal of Cd and Pb. The maximum removal of Cd and Pb was achieved at pH (6), initial concentration of metal ions (30 mg L⁻¹), the content of D-TiO₂–NC (50 mg), contact time (30 min), and temperature (45 °C) with adsorption capacities of 147 and 145.5 mg g⁻¹, respectively. The D-TiO₂–NC has successfully followed the pseudo-second-order kinetics for the successful removal of Cd and Pb. However, the resulting data followed multilayer adsorption for the removal of Cd while monolayer adsorption for Pb onto the D-TiO₂–NC. The findings of the thermodynamic study revealed that the D-TiO₂–NC followed the endothermic and spontaneous adsorption process for the adsorption of Cd and Pb. Furthermore, D-TiO₂–NC can easily be used several times after washing with diluted HNO₃ for the adsorptive removal of Cd and Pb. Moreover, it is quantitatively adsorbed (> 90%) the Cd and Pb from the collected drinking water samples.

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The complex composition of real-produced wastewater from oil processing poses significant challenges for wastewater treatment. The employed conventional methods have disadvantages such as low efficiency, high-cost demand, secondary waste, adverse effects on the environment and need to be intensified. The combined treatment of coagulation (carried out with Al₂(SO₄)₃) and photocatalysis (UV/TiO₂) was studied on wastewater produced from a SOCAR (Pirallahi dry well) oil extraction plant and synthetic paracetamol-based wastewater. Two different dosages of Degussa P25 catalyst at different pH conditions and ion presence were studied. Characterization of the produced wastewater showed the complexity of the treated matrix given the presence of inorganic ions and aromatic and aliphatic contaminants, and an important parameter that was reduced through coagulation was turbidity. The initial concentration expressed as THC was 714 mg/L. At the end of the treatment, a THC value of 210 mg/L was reached.