Lomefloxacin Research Articles

Strategy of Constructing Ratio-Dependent Coordination Polymer probes and Their Film Application with a Smart Phone for Detection of Lomefloxacin Hydrochloride and Sodium Salicylate.

Lomefloxacin hydrochloride (LMFX) and sodium salicylate (SS) are important targets for real-time detection due to their widespread uses in daily life; accurate and portable monitoring of LMFX and SS is crucial for human health concerns accordingly. Developing a precise and smart platform for determination of the above analytes remains a significant challenge. Herein, a high-sensitivity platform incorporating a luminescence electrospinning film, self-designed smart-phone app, and portable 3D printing device has been developed to identify LMFX and SS. In this work, two heterometallic coordination polymers with two-dimensional layer structures have been synthesized based on 2,2'-oxidiacetic acid ligand (H2oda), namely, [LnPb(oda)2(CH3COO)]n [Ln = Eu (IMU-1); Tb (IMU-2)]. IMU-1 and IMU-2 were ratio-dependent luminescence probes, which could selectively and sensitively sense with LMFX and SS, respectively. Additionally, the synthesized electrospinning films incorporating IMU-1 and IMU-2 were employed to identify LMFX and SS. Both films could rapidly photograph and color-capture through a portable 3D printing device, along with a self-designed smart-phone app that enabled convenient and quick determination of the concentrations of the above analytes. Remarkably, the mechanism exploration indicated that electron transfer from ligands to analytes affected the antenna effect and further utilized the intrinsic luminescence of analytes along with the luminescence quenching of Ln3+ ions. Furthermore, a strategy for constructing ratio-based fluorescent probes by exploiting the luminescence of analytes and Ln3+ ions in host coordination polymers is proposed. This work provides a new insight by combining luminescence probes, portable devices, and a smart-phone app for real-time detection of drugs and food additives.

Quinolone antibiotics stimulate bacterial mercury methylation by Geobacter metallireducens GS-15

Bacterial mercury (Hg) methylation is critical for bioremediating Hg pollution, but the impact of emerging antibiotics on this process has rarely been reported. This study innovatively investigated the interactions between Hg-methylating bacteria of Geobacter metallireducens GS-15 and two quinolone antibiotics: lomefloxacin (LOM) and ciprofloxacin (CIP) at 5 μg/L. Short-term LOM exposure increased methylmercury (MeHg) yield by 36 % compared to antibiotic-free conditions, caused by hormesis to alter bioactivities of single GS-15 cells. Long-term CIP exposure led to more antibiotic resistance and mercury tolerance in GS-15 cells, doubling MeHg productivity and significantly increasing expression of Hg methylation (hgcA by 95 folds) and antibiotic resistance (gyrA by 54 folds) genes, while mercury resistance gene merA only increased by 2.5 folds than without selective pressure. These results suggest quinolone antibiotics at environmentally contaminated concentrations stimulate bacterial Hg methylation to form highly toxic MeHg, raising considerable concern for the Hg-antibiotic complex in contaminated environments.

Development of a Sensitive Monoclonal Antibody-Based Colloidal Gold Immunochromatographic Strip for Lomefloxacin Detection in Meat Products.

Lomefloxacin (LOM), an antibiotic crucial for preventing various animal diseases in animal husbandry, can pose serious health risks when found in excessive amounts in meat products. The development of highly specific and sensitive colloidal gold immunochromatographic test strips is essential for the accurate detection of this class of antibiotics. Our study utilized a monoclonal antibody (mAb) assay and immunochromatographic strips to detect lomefloxacin residues in meat products. The results showed minimal cross-reactivity with other structural analogs, with a maximum half inhibitory concentration (IC50) of 0.93 ng/mL and a linear range of 0.38 to 2.3 ng/mL for the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA). The recovery of LOM was 80% to 120%, with an average coefficient of variation below 5%. The immunochromatographic strip test results showed a visual detection limit of 2.5 ng/g, meeting the market requirements for the test. This study highlights the significance of specific and sensitive testing methods for detecting lomefloxacin, ensuring consumers' safety and health.

A green and economically efficient adsorbent made by longan seed for the treatment of fluoroquinolone antibiotics in water

In this study, a green and economically efficient adsorbent was prepared from discarded longan seed. Hydrochloric acid-modified longan seed biochar (HNSB), as the final product, possesses excellent adsorption properties. BET characterization of HNSB demonstrates impressive porous properties with a specific surface area of 420.58 m2/g. Batch adsorption experiments were conducted with gatifloxacin (GAT), norfloxacin (NOR), and lomefloxacin (LOM) as representatives of typical fluoroquinolone antibiotics (FQs). The adsorption capacity of HNSB for FQs exceeded 40% of that of commercial activated carbon. The sustained effective time of HNSB dynamic adsorption for treating high concentrations of FQs wastewater was more than 20 h. Adsorption kinetics and isotherms were fitted by the pseudo-second-order model and the Langmuir model. The adsorption mechanism includes the pore-filling effect, electrostatic attraction, reduction reaction, hydrogen bonding, π-π interaction, and hydrophobicity. This study provides an economic and feasible strategy for the engineering application of agricultural wastes in pharmaceutical wastewater treatment.

Solvent-free synthesis of defective Zr-based metal–organic framework from waste plastic bottles for highly efficient lomefloxacin removal

Large amount of polyethylene terephthalate (PET) plastics waster and emerging contaminants in water, including fluoroquinolone antibiotics, pose challenges to human survival. In this work, a green synthesis scheme is proposed in which the defective UiO-66 (d-UiO-66) is fabricated via a solvent-free routine by using PET plastics waster as raw materials for lomefloxacin (LOM) removal. In comparison with defect-free UiO-66, the created defect imparts d-UiO-66 with higher porosity and abundant defective Zr sites, which are beneficial to boost LOM adsorption. As expected, d-UiO-66 exhibited excellent LOM adsorption performances, showcasing a saturation adsorption capacity of 588 mg g−1 and a kinetic rate constant of 0.204 g mg−1 h−1, which are 3.5 and 2.0 times higher than those of the pristine UiO-66, respectively. Remarkably, the LOM saturation adsorption capacity of d-UiO-66 surpasses that of all reported adsorbents. Mechanism study reveals that this outstanding adsorption performance of d-UiO-66 is mainly ascribed to the abundant defective sites, high porosity, together with the strong hydrogen bonding interaction and π-π stacking interaction between d-UiO-66 and LOM. Therefore, the d-UiO-66 obtained by the solvent-free method can not only effectively upcycle PET plastic waster, but also efficiently remove LOM, demonstrating a potential routine to simultaneous address the solid PET waster and wastewater.

Preparation of Zn/Zr-MOFs by microwave-assisted ball milling and adsorption of lomefloxacin hydrochloride and levofloxacin hydrochloride in wastewater

The Zn/Zr-MOFs were synthesized via microwave-assisted ball milling and subsequently characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The thermal stability of the Zn/Zr-MOFs was evaluated through thermogravimetry (TGA). The results demonstrated the exceptional adsorption properties of the Zn/Zr-MOFs towards Lomefloxacin hydrochloride and Levofloxacin hydrochloride. At a concentration of 30 ppm for Lomefloxacin hydrochloride, the addition of 30 mg of Zn/Zr-MOFs material resulted in an adsorption capacity of 179.2 mg•g−1. Similarly, at a concentration of 40 ppm for Levofloxacin hydrochloride, the addition of 30 mg Zn/Zr-MOFs material led to an adsorption capacity of 187.1 mg•g−1. Kinetic analysis revealed that the experimental data aligned well with a pseudo-second order kinetic model. Overall, these findings highlight the significant potential application of Zn/Zr-MOF materials in wastewater treatment.

Study of the impurity profile of photodegradation in lomefloxacin hydrochloride ear drops using liquid chromatography combined with ion trap/time-of-flight mass spectrometry.

Lomefloxacin hydrochloride ear drops are highly unstable to light and prone to produce photodegradation impurities. These impurities might be related to the phototoxicity of lomefloxacin, which could seriously threaten the health of patients. In this article, the photodegradation impurity profile in lomefloxacin hydrochloride ear drops was studied for further improvement of quality control of the drug. By studying the chromatographic behavior of photodegradation impurities, the photodegradation impurities in lomefloxacin hydrochloride ear drops were separated and detected effectively. Liquid chromatography combined with ion trap/time-of-flight mass spectrometry was applied to characterize the structures of the photodegradation impurities in lomefloxacin hydrochloride ear drops. The structures of 17 impurities in lomefloxacin hydrochloride ear drops were elucidated based on high-resolution MSn data in positive ion mode, 12 of them being unknown impurities. The structural characteristics and fragmentation patterns of the photodegradation impurities were also studied. The study of the photodegradation impurity profile in lomefloxacin hydrochloride ear drops provides a scientific basis for quality control of these ear drops and ensures the safety of drug use by the public.

Quantum dot-based fluorescence-linked immunosorbent assay for the rapid detection of lomefloxacin in animal-derived foods

Lomefloxacin (LMF), a third-generation fluoroquinolone antibacterial agent, is often used to treat bacterial and mycoplasma infections. However, due to its prolonged half-life and slow metabolism, it is prone to residues in animal-derived foods, posing a potential food safety risk. Therefore, it is particularly urgent and important to establish a method for detecting lomefloxacin. In this study, direct and indirect competitive fluorescence-linked immunosorbent assay (dc-FLISA and ic-FLISA) based on quantum dots (QDs) was established for the detection of LMF. As for dc-FLISA, the half-maximal inhibitory concentration (IC50) and limit of detection (LOD) were 0.84 ng/mL, 0.04 ng/mL, respectively, the detection ranges from 0.08 to 9.11 ng/mL. The IC50 and LOD of ic-FLISA were 0.43 ng/mL and 0.03 ng/mL, respectively, meanwhile the detection ranges from 0.05 to 3.49 ng/mL. The recoveries of dc-FLISA and ic-FLISA in animal-derived foods (milk, fish, chicken, and honey), ranged from 95.8% to 105.2% and from 96.3% to 103.4%, respectively, with the coefficients of variation less than 8%. These results suggest that the dc-FLISA and ic-FLISA methods, which are based on QD labelling, are highly sensitive and cost-effective, and can be effectively used to detect LMF in animal-derived foods.

Red mud-based CoFe2O4 activated by ball milling as effective peroxymonosulfate activator for the degradation of lomefloxacin hydrochloride: Preparation & activation, application and degradation mechanism

In this study, red mud-based CoFe2O4 (CoFe2O4/RM) was firstly prepared via a sol–gel method, and then activated through ball milling to obtain the catalyst of Ball-milled CoFe2O4/RM (BM-CoFe2O4/RM). The BM-CoFe2O4/RM catalyst was applied as a high-efficiency activator of peroxymonosulfate (PMS) for the degradation of lomefloxacin hydrochloride (LOM-HCl). The LOM-HCl (100 mg/L) could be removed 86.36 % after 12 min treatment under the optimal reaction parameters (BM-CoFe2O4/RM dosage of 1.33 g/L, PMS concentration of 5 mmol/L and nature pH 6.59 ± 0.1). The comparative experiments revealed that the apparent rate constant of LOM-HCl degradation of BM-CoFe2O4/RM (0.1091 min−1) was approximately 1.6 times that of CoFe2O4/RM (0.0701 min−1). A series of characterizations demonstrated that the physicochemical properties of CoFe2O4/RM, including defective structures, crystallinity of high active components, exposures of Co (II) and Fe (II) and electrical conductivity, could be improved via ball milling, causing the increase of the catalytic activity of CoFe2O4/RM. Combined with the results of Electron spin resonance (ESR), X-ray photoelectron spectrometer (XPS) and quenching experiments, the possible catalytic mechanism of PMS activated by BM-CoFe2O4/RM for LOM-HCl degradation was proposed. Combined with the density functional theory (DFT) calculation and liquid chromatography-mass spectrometer (LC-MS), the possible vulnerable sites and possible degradation pathways of LOM-HCl were obtained. The recycling experiments and XPS demonstrated that BM-CoFe2O4/RM had good stability, and the catalytic activity of the BM-CoFe2O4/RM after use could be regenerated by thermal treatment. The biological toxic experiment suggested that the toxicity of LOM-HCl solution treated by the BM-CoFe2O4/RM + PMS system was effectively reduced. The work not only provides a simple and high-efficiency method for improving the catalytic activity of CoFe2O4/RM, but also opens novel insights into the Ball-milled CoFe2O4/RM as an effective PMS activator for antibiotic wastewater treatment.

One-step synthesis of CoxS/Ni3S2@NF on 3D nickel foam with different sulfur sources as a novel heterogeneous catalyst efficient activation of peroxymonosulfate in lomefloxacin degradation

In this study, we have successfully synthesized Co9S8/CoS/Ni3S2 and Co3S4/Ni3S2 materials in situ on three-dimensional (3D) nickel foam (NF) substrates using a one-step hydrothermal process with different sulfur sources. Under the experimental conditions of catalyst dosage of 0.50 cm × 0.50 cm and peroxymonosulfate (PMS) dosage of 0.30 g/L, the Co3S4/Ni3S2@NF catalyst exhibited superior catalytic performance in activating PMS and degrading 91.0 % of lomefloxacin (LOM) as compared to 76 % of Co9S8/CoS/Ni3S2@NF. Both Co9S8/CoS/Ni3S2@NF and Co3S4/Ni3S2@NF showed excellent stability and performed effectively over a wide pH range. The Co9S8/CoS/Ni3S2@NF and Co3S4/Ni3S2@NF demonstrated significant differences in morphology, crystal plane properties, surface functional groups, chemical composition, elemental valence states, and coordination environment as revealed by XRD, TEM, SEM, FTIR, and XPS analyses, contributing to their distinct mechanisms and performance in LOM degradation. Additionally, the NF acted as a support carrier, exposing multiple active sites to enhance electron transport and providing a nickel source for the catalytic reaction. The degradation of LOM in the CoxS/Ni3S2@NF&PMS system was thoroughly investigated, revealing the involvement of SO4−, OH, 1O2, and electron transfer in the process. Additionally, the mechanism of PMS activation and the pathway of LOM decomposition in the reaction system were elucidated by theoretical analysis. Furthermore, the ecotoxicity of the by-products generated during LOM degradation was assessed using the ECOSAR software. In summary, the CoxS/Ni3S2@NF catalysts proved to be efficient, stable, easily prepared, environmentally friendly, and recyclable heterogeneous nanocomposites. It is a promising candidate for heterogeneous PMS process.

Dual electron reservoirs: Synergistic photocatalytic degradation of antibiotics by oxygen vacancy-rich BiOBr nanoflowers and magnetic carbon nanotubes

Rational modulation of surface oxygen vacancies (OVs) and efficient charge separation are important factors for improving solar energy conversion efficiency. However, the synergistic relationship between OVs and magnetic carbon nanotubes (The magnetic carbon nanotubes in this paper are abbreviated as CNFe) is still unclear. As a result, oxygen vacancy-rich BiOBr/CNFe photocatalysts were created in this study by in situ growing OVs-BiOBr on bamboo-shaped CNFe. The formation of oxygen vacancies introduced a defect band where electrons could directly transition to the oxygen vacancies for storage, suppressing the recombination of photoinduced charge carriers. Meanwhile, CNFe acted as an electronic bridge to rapidly transfer electrons from the conduction band of BiOBr to CNFe, thus retaining the powerful redox-capable photogenerated carriers and significantly improving the photocatalytic activity. As a result, the synthesised OVs-BiOBr/CNFe (O-BCN) photocatalyst exhibited 80.8 % degradation of lomefloxacin hydrochloride within 3 h, with an apparent rate constant 4.4 times higher than BiOBr. This work provides new insights into the preparation of efficient photocatalysts by regulating surface defects and bridging effects.

Fe-nanocluster embedded biomass-derived carbon for efficient photo-Fenton-like activity in water purification

Single-atom catalysts (SACs) as photo-Fenton-like catalysts have attracted widespread attention in water purification. However, the development of SACs with renewability, cleanliness, high mass loading, and raw material abundance is a formidable challenge to achieve efficient pollutant removal. In this study, we fabricated high-performance Fe-nanocluster embedded biomass-derived carbon (Fe/Bio-C) from Ficus altissima wastes for quinolone antibiotics degradation. The high-angle annular dark-field scanning transmission electron microscopy with aberration correction (AC-HAADF-STEM) and X-ray absorption fine structure spectroscopy (XAFS) revealed that the Fe/Bio-C exhibited a porous structure with abundant Fe-N4 active sites. The Fe/Bio-C catalysts achieved an exceptional efficiency of 98.6 % for the removal of the representative quinolone antibiotic, namely lomefloxacin (LOM), within 30 min. Furthermore, an in-depth exploration was conducted to assess the influence of reaction parameters on degradation performance, kinetics, toxicity, and mechanism. The free radical quenching experiments and electron paramagnetic resonance (EPR) spectra demonstrated the existence of ·O2−, 1O2, ·OH, SO4·− in the reaction system and the ·O2− radicals played a relatively important role in the degradation progress. This work broaden the avenue for constructing metal-nanocluster photocatalysts with the high reactivity, low metal leaching, and universality to various pollutants.

A novel red mud-based Co3O4–Fe2O3–Co2AlO4 composite as a peroxymonosulfate activator for effective degradation of lomefloxacin hydrochloride

The possible catalytic mechanism of PMS activated by Co–Fe/RM.

Magnetic activated carbon from spent coffee grounds: iron-catalyzed CO2 activation mechanism and adsorption of antibiotic lomefloxacin from aqueous medium.

The facile fabrication of low-cost adsorbents possessing high removal efficiency and convenient separation property is an urgent need for water treatment. Herein, magnetic activated carbon was synthesized from spent coffee grounds (SCG) by Fe-catalyzed CO2 activation at 800°C for 90min, and magnetization and pore formation were simultaneously achieved during heat treatment. The sample was characterized by N2 adsorption-desorption, XRD, VSM, SEM, and FTIR. Batch adsorption experiments were conducted using lomefloxacin (LMO) as the probing pollutant. Preparation mechanism was revealed by TG-FTIR and XRD. Experimental results showed that Fe3O4 derived from Fe species can be reduced to Fe by carbon at high temperatures, followed by subsequent reoxidation to Fe3O4 by CO2, and the redox cycle between Fe and Fe3O4 favored the formation of pores. The promotion effects of Fe species on CO2 activation can be quantitatively reflected by the yield of CO as the signature gaseous product, and the suitable activation temperate range was determined to be 675 to 985°C. The BET surface area, total pore volume, and saturated magnetization value of the product were 586 m2g-1, 0.327 cm3g-1, and 11.59 emu g-1, respectively. The Langmuir model was applicable for the adsorption isotherm data for LMO with the maximum adsorption capacity of 95mgg-1, and thermodynamic analysis revealed that the adsorption process was endothermic and spontaneous. This study demonstrated that Fe-catalyzed CO2 activation was an effective method of converting SCG into magnetic separable adsorbent for LMO removal from aqueous medium.

Activation of peroxymonosulfate with MgO/Co3O4 catalyst for efficient decomposition of Lomefloxacin: activation mechanism, degradation pathway, and toxicity assessment

To improve the degradation efficiency of PMS-advanced oxidation system, in this paper, a MgO/Co3O4 composite catalyst was prepared by Co3O4 modification on MgO surface through simple hydrothermal process and subsequent calcination. Then, advanced oxidation system of MgO/Co3O4 activated peroxymonosulfate (PMS) was established to degrade Lomefloxacin (LMF). The identification results of active substances showed that, •OH and SO4•−, •OH and 1O2 produced in MgO/Co3O4/PMS system contributed greatly to the degradation of LMF, and ∙O2−also played a certain role, but it was not as good as the first three active substances. Oxygen vacancies and hydroxyl groups on the surface of MgO/Co3O4 accelerate the electron transfer between Co2+ and Co3+, thus improving the cycle efficiency of Co3+/Co2+. Consequently, degradation rate of Lomefloxacin reached 97.88% in 30 min using MgO/Co3O4 +PMS system. Especially, MgO/Co3O4 shows good stability, and no significant change was observed in its catalytic performance during 6 consecutive cycles, which proved that MgO/Co3O4 showed good practical application value.

Revealing discrepancies and drivers in the impact of lomefloxacin on groundwater denitrification throughout microbial community growth and succession

The coexistence of antibiotics and nitrates has raised great concern about antibiotic's impact on denitrification. However, conflicting results in these studies are very puzzling, possibly due to differences in microbial succession stages. This study investigated the effects of the high-priority urgent antibiotic, lomefloxacin (LOM), on groundwater denitrification throughout microbial growth and succession. The results demonstrated that LOM’s impact on denitrification varied significantly across three successional stages, with the most pronounced effects exhibited in the initial stage (53.8% promotion at 100 ng/L-LOM, 84.6% inhibition at 100 μg/L-LOM), followed by the decline stage (13.3–18.2% inhibition), while no effect in the stable stage. Hence, a distinct pattern encompassing susceptibility, insusceptibility, and sub-susceptibility in LOM's impact on denitrification was discovered. Microbial metabolism and environment variation drove the pattern, with bacterial numbers and antibiotic resistance as primary influencers (22.5% and 15.3%, p < 0.01), followed by carbon metabolism and microbial community (5.0% and 3.68%, p < 0.01). The structural equation model confirmed results reliability. Bacterial numbers and resistance influenced susceptibility by regulating compensation and bacteriostasis, while carbon metabolism and microbial community impacted energy, electron transfer, and gene composition. These findings provide valuable insights into the complex interplay between antibiotics and denitrification patterns in groundwater.

Inhibition of algal blooms by residual antibiotics in aquatic environments: Design, screening, and validation of antibiotic alternatives

Water blooms frequently appear in the aquatic environment with global warming. However, traditional methods for treating water bloom usually require the addition of algaecides, which may lead to secondary environmental pollution problems in the water environment. To solve this problem, researchers have initiated efforts to harness pre-existing chemical substances within aquatic environments to regulate algal blooms, thereby pioneering novel avenues for water body management. Therefore, an integrated approach involving molecular docking, molecular dynamics simulations, three-dimensional quantitative structure-activity relationship (3D-QSAR), and toxicokinetics methods were utilized for the molecular modification of fluoroquinolone antibiotics, to design and screen fluoroquinolone substitutes with improved toxicity of cyanobacteria and green algae, functionality, and environmental friendliness. A total of 143 fluoroquinolone alternatives were designed in this study, and lomefloxacin-6 (LOM6) was found as the optimum alternative to lomefloxacin (LOM), with increased toxicity to cyanobacteria and green algae by 31 % and 72 %. Molecular docking of LOM before and after modification with seven other cyanobacterial and green algal photosynthetic proteins revealed that LOM6 exhibited varying degrees of increased toxicity towards 6 of these photosynthetic proteins, of which 2J96 protein increased the most (136.25 %). It shows that the residual LOM6 in the water environment has a certain inhibitory effect on the algae bloom. In addition, results showed that LOM6 had synergistic toxic effects on cyanobacteria and green algae with other pollutants residual in the aqueous environment, such as trichloroethyl phosphate, triethyl phosphate, perfluorononanoic acid, perfluorooctanoic acid. This indicates that LOM6 has better algal removal effectiveness in aqueous environments where organophosphate flame retardants and perfluorinated compounds exist together. In this paper, a novel method was developed to remove cyanobacteria and green algae in water environment and reduce the secondary pollution through theoretical simulation, which provides theoretical support for the control of water blooms.

Amino acid functionalized metal oxide nanocomposite for the removal of fluoroquinolones

Antibiotic consumption has increased globally, and its discharge into water bodies at concentrations ranging from a few ng/L to mg/L has a detrimental effect on the ecosystems. Amino acid functionalized nickel ferrite nanoparticles were chosen to improve the stability of bare nanoparticles and prevent oxidation and leaching ions in nanoparticles thereby targeting the antibiotics in the contaminated water bodies. The removal of ciprofloxacin and lomefloxacin hydrochloride in the aqueous phase was investigated using a hydrothermally synthesized L-Leucine functionalized nickel ferrite nanocomposite (NFO@L). Various analytical techniques were used to analyze L-Leucine functionalized nickel ferrite, and the nanocomposite's average particle diameter was determined to be between 11 and 15 nm. The maximal measured zeta potential was −21.5 mV. Fourier transform infrared spectroscopy (FTIR), ninhydrin assay and X-ray diffraction (XRD) analysis confirmed the attachment of L-Leucine onto nickel ferrite. The nanocomposite's surface-to-volume ratio was calculated to be 92.916 m2/g. The S-shaped curve from the vibrating sample magnetometer analysis reflected the superparamagnetic behaviour of the nanocomposite with a saturation magnetization of 0.665 emu/g. Various parametric experiments were conducted, in which 93.549% ciprofloxacin was removed in 120 min at 303 K, pH 8 and NFO@L dosage of 100 mg in 100 mL whereas 75.192% lomefloxacin hydrochloride was removed in 140 min at 333 K, pH 9 and NFO@L dosage of 70 mg in 100 mL. The plot of experimental datum in kinetic and isotherm studies fitted well with the Pseudo second order kinetic model and Langmuir isotherm. There was no evidence of iron ions leaching from the final analyte. The recycle and regeneration studies showed good stability with a small reduction after four cycle runs. Based on these findings, the Leucine functionalized nickel ferrite nanocomposite could be a potent adsorbent for the removal of low-concentrated ciprofloxacin and lomefloxacin hydrochloride in the wastewater.

Covalent assembly synthesis of covalent organic framework and MXene based composite for the adsorption of fluoroquinolones

Widespread use of fluoroquinolones (FQs) leads to its continuous excretion and release into the environment, resulting in the accumulation in water, animal-derived food etc., and posing a threat to environment and humans. Thus, the development of highly efficient FQs removal methods is of great significance. Herein, a composite (COF@MXene) was manufactured using a covalent assembly synthesis strategy by connecting covalent organic frameworks (COF) and NH2-MXene through a Schiff-base reaction. COF@MXene had the advantages of both COF and MXene, not only had good crystallinity, thermal stability and rich functional group properties, but also had high protein exclusion ability (Exclusion efficiency>97%) and good adsorption capacities for FQs including ciprofloxacin (CIP), lomefloxacin (LOM), moxifloxacin (MOX), gatifloxacin (GAT) and levofloxacin (LEV). The maximal adsorption capacities for them ranged from 54.63 to 147.91 mg·g−1, which were higher than those of COF (15.99–64.06 mg·g−1) and MXene (27.58–33.92 mg·g−1). The adsorption experimental data of adsorption isotherm and kinetics separately followed the Langmuir and pseudo-second-order models. Through density functional theory (DFT), Forcite calculation, UV-Vis and XPS analyses, pore size selectivity, electrostatic and hydrogen bond interactions were determined as the main driving forces for FQs adsorption. Finally, COF@MXene coupled with HPLC-DAD was employed for the analysis of FQs from water, egg and drug samples, and the recoveries were satisfactory. This work reported a covalent assembly synthesis strategy for the preparation of COF@MXene composite for FQs removal. This approach may establish a viable route for gentle fabrication of COF and MXene based composites for various applications.

Readily separable and stable CoFe2O4 beads for activating peroxymonosulfate to degrade lomefloxacin hydrochloride: Optimization, performance and degradation mechanism

CoFe2O4 is regarded as a star material because of its high catalytic activity and excellent separation performance. However, metal-ion dissolution and collection difficulty of powdery CoFe2O4 in practical applications are still critical scientific issues, which will not only cause new environmental risks but also may result in partial loss of catalysts. In this work, buoyant CoFe2O4-loaded hollow glass microspheres embedded in sodium alginate beads (CHS) for activating peroxymonosulfate (PMS) to degrade lomefloxacin hydrochloride (LMH) were successfully prepared by an impregnation-precipitation-gel method. The experimental results showed that the heterogeneous catalytic system (CHS + PMS) displayed 9.5-, 7.7- and 6.6-times degradation rates (kobs) towards LMH than that of leached Fe + PMS, Co + PMS, and Fe + Co + PMS homogeneous systems, respectively. More importantly, CHS could effectively alleviate the dissolution of metal ions due to the coordination of the carboxylate group on the alginate to the Co and Fe sites on the surface of CoFe2O4, ultimately the leached concentration of Co (0.089 mg/L) and Fe (0.014 mg/L) ions from CHS were only about 11.1% and 16.5% of the powdery CoFe2O4, respectively. Primary radicals involved in the LMH degradation process were ·OH and SO4·- through EPR characterization and quenching experiments. This study offers the possibility to design practical potential heterogeneous catalyst for stable activation of PMS.