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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]