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A comparative study of Cu-impregnated ZnO and Ni-impregnated ZnO for the sonophotocatalytic degradation of cefixime in aqueous solution under visible light irradiation was carried out. Sonophotocatalysts were prepared by using a wet impregnation method and characterised using different spectroscopic techniques. Sonophotocatalytic efficiency of degradation is superior to photolysis, sonolysis, photocatalysis and sonocatalysis. Different operational parameters like pH, catalyst dosage, different enhancers, scavenger's effect, initial concentration of drug, reusability of catalyst and catalyst settling time were optimised. Optimum time of 30 min was found for the 45.7% degradation of cefixime using Cu-ZnO and 42.2% degradation using Ni-ZnO photocatalysts at pH 10. The degradation of cefixime increased from 75.3% to 100% with 5 mmol of hydrogen peroxide using 0.1 g/ L of Cu-ZnO and 99.8% using 0.15 g/L of Ni-ZnO, while other oxidising agents were found less effective using (Cu–ZnO-Ni-ZnO) photocatalyst. A very little decrease in degradation was observed with different types of scavengers. Catalyst reusability was checked up to three cycles and good results up to three cycles were achieved and followed pseudo-first-order kinetic model. Furthermore, the sonophotocatalytic activity was tested for real pharmaceutical wastewater resulting in 91 and 89% removal of total organic carbon (TOC) using (Cu-ZnO-Ni-ZnO), respectively. The proposed method was successfully applied on commercial and synthetic sample with satisfactory results. [ABSTRACT FROM AUTHOR]

BACKGROUND: Copper plays a leading role in the electronics industry. Drastic innovation and fast obsolescence rate raise the demand for copper for electrical and electronic equipment. The high amount of electronic waste discarded is considered the primary alternative source and is now seen as a secondary reservoir for copper metal. Besides the economic impact, copper interferes with selective recovery of other metals such as critical, precious and rare earth elements from electronic waste. RESULTS: In this work, to purify acid leach solution of electronic waste from Cu(II) ions, a selective sorbent was synthesized. A Cu(II) specified ligand, α‐benzoinoxime, was impregnated with magnetic nanoparticle‐modified activated carbon and utilized as magnetic solid‐phase sorbent. The synthesized sorbent was analysed for its morphological and other characteristic properties. CONCLUSION: The study indicates that percent recovery increased from 89% to >95% after impregnation. Complexation between Cu(II) and α‐benzoinoxime‐modified activated carbon caused the sorbent to attain higher retention at pH > 8.5. Sorption capacity calculated from Langmuir sorption isotherm was 147 mg g−1, while the sorption process follows a pseudo‐second‐order kinetic model. The sorbed Cu(II) was quantitatively (>97%) eluted with 1 mol L−1 nitric acid. The method was validated with standard reference material GF10928752‐Aldrich. Results show that the synthesized sorbent is good for Cu(II) masking and recovery, even if applied to samples with a complex sample matrix. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

An eco-friendly efficient supramolecular solvent-based method was developed for extraction and determination of selected non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac sodium, caffeine and paracetamol in water samples followed by detection with high-performance liquid chromatography. Supramolecular solvent (SUPRAs) with composition of 400 μL of 1-undecanol as reverse micelles in dispersing solvent of 15% tetrahydrofuran (THF) solution in water at pH 4 used as extracting solvent for selected NSAIDs. Various factors affecting the extraction efficiency of NSAIDs like amount of 1-undecanol, percentage of THF, composition of SUPRA, pH, vortex time and sample amount were studied. Limit of detection (S/N = 3) and quantification (S/N = 10) were 0.02 and 0.08 μg mL-1 for paracetamol, 0.006 and 0.02 μg mL-1 for caffeine, 0.06 and 0.2 μg mL-1 for diclofenac sodium with linear range of 0.1-12 μg mL-1. The inter-day relative standard deviation (RSD) values were 3.1%-5.2%, 3.3%-4.2% and 2.2%-3.6%, while for intra-day the RSD values obtained were 2.4%-4.1%, 1.4%-3.1% and 1.5%-4.1% for paracetamol, caffeine and diclofenac sodium, respectively. The proposed method has been applied successfully to the spiked water samples and recoveries were found in the range of 89.5%-94.6% for tape water, 88.5%-92.8% for canal water and 90.0%-95.2% for industrial wastewater samples was obtained. [ABSTRACT FROM AUTHOR]

Liquid–liquid microextraction method based on supramolecular solvent was proposed for analysis of dinitroaniline herbicides (pendimethalin and trifluralin) residue in water and onion samples. In the present method, reverse micelles of undecanol (250 mg 1-undecanol) dispersed in tetrahydrofuran and water was used as supramolecular solvent. The parameters affecting the extraction efficiency of herbicides like pH, amount of 1-undecanol, percentage of tetrahydrofuran (THF), composition, volume of supramolecular solvent and vortex time were studied. At optimum conditions, the linear range for both herbicides was from 0.03 to 100 mgL−1. The method was found selective for determination of dinitroaniline herbicides in the presence of coextractants of onion samples. The percentage recoveries were found 97.5–100% and 91.2–95.2% for water and onion samples, respectively. Limit of detection (S/N = 3) of pendimethalin and trifluralin was in the range of 3.0–5.5 µgL−1 for water samples and 7–11 µgL−1 for onion samples. Preconcentration factor was found to be 63. Calculated analytical eco-scale value (>75) for the proposed method fulfilling principles of green analytical chemistry. [ABSTRACT FROM AUTHOR]

Traditionally, sciences like physics, mathematics, and engineering have been considered subjects for males only. As a result, women scientists in the area of physics and mathematics throughout the world are, [...]

The presence of heavy metals in water causes serious problems and their treatment before incorporating into the water body is a challenge for researchers. The present study was conducted to compare the sorption study of Ni (II) using silica gel, amberlite IR-120 and sawdust of mulberry wood in batch system under the influence of pH, initial Ni (II) concentration and contact time. It was observed that sorption process was depending upon pH and maximum sorption was achieved at pH 7.0. Kinetic data were well fitted into pseudo-second order kinetic model due to high R2 values and closeness of experimental sorption capacity and calculated sorption capacity of pseudo-second order. Isotherms study showed that Langmuir is one of the most suitable choices to explain sorption data due to high R2 values. The monolayer sorption capacities of silica gel, amberlite IR-120 and sawdust were found to be 33.33, 25.19, and 33.67 mg g−1, respectively. Desorption study revealed that NaCl is one of the most appropriate desorbent. It may be concluded from this study that sawdust is a suitable sorbent due to low cost, abundant availability and recycling of the materials for further study. [ABSTRACT FROM AUTHOR]

In this study, silica-coated magnetic nanoparticles with mixed hemimicelles were used for the solid-phase extraction of chlorophenols such as 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol from aqueous samples. Magnetic nanoparticles (Fe3O4) were prepared by coprecipitation method, modified with silica (SiO2) and characterized using different techniques. The effect of various parameters including solution pH, contact time, amount of adsorbent and volume of surfactant (cetyltrimethylammonium bromide [CTAB]) was evaluated in batch experiments for the maximum adsorption of chlorophenols. The results showed that the percentage removal of 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol was 85%, 87%, 95% and 96%, respectively, achieved by using Fe3O4@SiO2 at neutral pH 7 with 150 mg/g of CTAB amount in 60 min. For the extraction of chlorophenols, type of eluent, volume of eluent and extraction time were optimized. The limit of detections of chlorophenols ranged from 0.02 to 0.07 μg/L using high-pressure liquid chromatograph with UV detector. The proposed method was applied for the determination of chlorophenols in real water samples including groundwater, river water, wastewater and tap water. The percentage recovery of 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol was in the range of 95%–99%, respectively. [ABSTRACT FROM AUTHOR]