Removal Of Levofloxacin Research Articles

Removal of levofloxacin from aqueous solution by green synthesized magnetite (Fe3O4) nanoparticles using Moringa olifera: Kinetics and reaction mechanism analysis

Levofloxacin antibiotic is frequently being detected in the environment and regarded as an emerging contaminant. The present study was focused on the green synthesis of magnetite (Fe3O4 – gINPs) nanoparticles from Moringa olifera and its efficiency for removal of levofloxacin from aqueous solution. The adsorbent magnetite nanoparticles (Fe3O4) were prepared by green synthesis using Moringa olifera and coprecipitation method. Characterizations analyses of both chemically and green synthesized nanoparticles were performed by SEM, XRD, and FTIR. The average crystallite size of gINPs was 14.34 nm and chemically synthesized was 18.93 nm. The performance of the synthesized product was evaluated by adsorption capacity and removal efficiency. The parameters considered included adsorbent (gINPs) dosage, initial concentration of adsorbate, pH, contact time, and temperature. The obtained data were fitted to kinetic and isotherm models to determine the mechanism. Adsorption batch experiments were conducted to determine the reaction mechanism by studying kinetics while fitting isotherm models for samples analyzed using HPLC at 280 nm. Results showed that 86.15% removal efficiency of 4 mg L-1 levofloxacin was achieved by 100 mg L-1 gINPs in 24 h contact time when all other parameters (pH 7, temperature 25 °C) were kept constant. The maximum adsorption capacity achieved at equilibrium was 22.47 mg/g. Further, it was identified as a pseudo-second-order model with R2 = 0.965 for adsorption kinetics while isotherm data better fitted to the Freundlich model compared to Langmuir isotherm with R2 = 0.994. The potential pathway determined for levofloxacin removal was chemisorption with minor diffusion, multilayer, spontaneous and exothermic processes on the gINPs (Fe3O4). Reusability experiments were conducted in four cycles and removal efficiency varied from 85.35% to 80.47%, indicating very high potential of the adsorbent for re-use.

Three porous shapeable three-component hydrogen-bonded covalent-organic aerogels as backfill materials in a simulated permeable reactive barrier (PRB) for trapping levofloxacin

Levofloxacin (LEV) infiltrated in groundwater has threatened the safety of drinking water. For in-situ remediation of LEV-contaminated groundwater, there exists a main challenge of exploiting proper high efficient backfill medium in utilizing charming permeable reactive barriers (PRBs). Herein, three porous shapeable three-component hydrogen-bonded covalent organic aerogels (HCOA-1, HCOA-2 and HCOA-3) were fabricated based on a multiple-linking-site strategy to evaluate for adsorptive removal of LEV. The three HCOAs exhibited satisfactory performance in LEV adsorption that could integrate high adsorption capacity, good antiion interference, excellent recyclability and wide pH tolerance. The different regularity of kinetics and isotherms of three HCOAs signified that electrostatic effect, pore preservation, hydrogen bonding probably govern the adsorption process in combination, coupling with π-π electron-donor-acceptor (EDA), dipole-dipole and hydrophobic-hydrophobic interaction besides. In addition, the response surface methodology (RSM) was employed for studying the single and synergetic effects of selected variables and optimizing operation conditions. Furthermore, a laboratory PRB column packed with processable HCOA-2 was set up to investigate the LEV removal, and the breakthrough data was explained by Adams-Bohart, Thomas, BDST and Yoon-Nelson models. We believe could hopefully bring HCOAs into the real in-situ remediation of such challenging and persistent LEV-polluted groundwater with further massive-scale efficiently.

Sustainable biochar/MgFe2O4 adsorbent for levofloxacin removal: Adsorption performances and mechanisms

The limitation of low efficiency and complicated separation after adsorption make the practical application of biochar a huge challenge. Here, one pomelo peel-derived magnetic biochar composite, biochar supported MgFe2O4 (BMF) was fabricated and adopted for Levofloxacin (LFX) adsorption. Adsorption behaviors and mechanisms were investigated by characterization analysis, batch experiments, and data modeling. Results indicated that adsorption could be strikingly influenced by pyrolysis temperature. Adsorption kinetic was well fitted by pseudo-second-order model. Adsorption isotherm was best fitted with Freundlich model. The maximum adsorption capacity was 115 mg g−1. Moreover, hydrophobic effect played a limited contribution according to dual-mode model analysis. LFX adsorption was spontaneous and endothermic. Adsorption mechanisms were ascribed to electrostatic interactions, H-bonding, functional groups complexation, and π-π electron donor–acceptor interactions. Besides that, BMF had the potential for repeated use. This research proposed a novel and promising method for LFX or other antibiotics adsorption removal.

Facile fabrication of TaON/Bi2MoO6 core–shell S-scheme heterojunction nanofibers for boosting visible-light catalytic levofloxacin degradation and Cr(VI) reduction

Developing excellent photocatalysts for antibiotics degradation and Cr(VI) reduction is of vital significance but still a big challenge. Herein, novel S-scheme heterojunction of TaON/Bi2MoO6 with a core–shell structure is constructed via an electrospinning-calcination-nitridation approach, where 2D Bi2MoO6 nanosheets are uniformly and firmly anchored on the surface of 1D TaON nanofibers. The optimal TaON/Bi2MoO6 with the TaON/Bi2MoO6 molar ratio of 1:1 manifests the highest catalytic activity towards levofloxacin (LEV) antibiotic degradation and Cr(VI) reduction under visible light. The exceptional photocatalytic performance is probably due to the synergistic effect of the favorable core–shell fiber-shaped structure and S-scheme hetero-structure, which enables the strong interfacial interaction between the constituents for effectively improving the visible-light absorption, boosting the separation and utilization efficiency of electron-hole pairs, and retaining the charge carriers with stronger redox capabilities. Of note, TaON/Bi2MoO6 possesses excellent stability and reusability. Photo-generated h+, •OH, and •O2– are the main reactive species accounting for LEV degradation, the detailed LEV degradation pathways are elucidated by detecting the intermediates using HPLC–MS and the toxicity of the intermediates are assessed by quantitative structure–activity relationship (QSAR) method. In addition, •O2– and e– are primarily responsible for Cr(VI) reduction. Further, a possible photocatalytic reaction mechanism for removal of LEV and Cr(VI) is proposed. This study provides some insights in fabricating high-performance S-scheme heterojunction photocatalysts for the efficient water purification.

Fe2P/biocarbon composite derived from a phosphorus-containing biomass for levofloxacin removal through peroxymonosulfate activation

Phosphorus-containing biomass represents one kind of sustainable and environmental-benign precursor for transition metal phosphide synthesis. Herein, we adopt abundant agricultural biomass of rice bran as both P and C precursor to fabricate iron phosphide/biocarbon composite. Through a ball-milling pretreatment coupled with a molten salt-assisted pyrolysis process, Fe2P/biocarbon composite (Fe2P/BC) with high specific surface area is obtained. The as-synthesized composite could be applied as environmental material for model antibiotic pollutant (levofloxacin, LEV) removal from aqueous solution through adsorption and peroxymonosulfate (PMS) activation. Under the typical reaction conditions of 0.25 g L−1 Fe2P/BC, 0.1 g L−1 PMS, pH 7 and room temperature, 96.60% of LEV (initial concentration 10 mg L−1) could be removed within 60 min. Through quenching experiments and electron paramagnetic resonance (EPR) tests, active species including SO4−•, •OH and 1O2 are found responsible for LEV degradation. Various reaction intermediates are detected by gas chromatography-mass spectrometry (GC–MS) and liquid chromatography-mass spectrometry (LC-MS), which enable us to propose the rational degradation pathways of LEV. Although the mineralization efficiency only reaches 39.02%, LEV degradation solution does show remarkably weakened antibacterial activity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538 compared with original LEV, indicating the possible low ecotoxicity of the developed Fe2P/BC-PMS system for environmental remediation.

The optimization of enzymatic oxidation of levofloxacin, a fluoroquinolone antibiotic for wastetwater treatment.

The global presence of antibiotics in the environment has created concerns about the emergence of antibiotic resistance bacteria and potential hazard to humans and the ecosystem. This work aims to study the removal of levofloxacin, a new generation fluoroquinolone antibiotic from aqueous solutions by enzyme mediated oxidation process and optimization of the conditions thereof by response surface methodology (RSM) using Box-Behnken design (BBD). For this study, experiments were conducted to analyze the effect of independent variables namely, pH, temperature, mediator concentration and antibiotic concentration on the degradation percentage of levofloxacin antibiotic using laccase enzyme derived from Trametes versicolor. The residual levofloxacin concentration was determined using high performance liquid chromatography (HPLC). On applying the quadratic regression analysis, among the main parameters, it was found that the percentage degradation was significantly affected by all the four variables. The predicted values for percentage degradation of levofloxacin were close to the experimental values obtained and the R2 (0.95) indicated that the regression was able to give a good prediction of response for the percentage degradation of levofloxacin in the studied range. The optimal conditions for the maximum degradation (99.9%) as predicted by the BBD were: temperature of 37°C, pH of 4.5, mediator concentration of 0.1mM and levofloxacin concentration of 5μgmL-1. The findings of the study were further extended to study the effect of partially purified enzymes isolated from Pleurotus eryngii, Pleurotus florida and Pleurotus sajor caju on the degradation of levofloxacin at concentrations ranging from as low as 0.1 to as high as 50µgmL-1 in synthetic wastewater utilizing the optimized conditions generated by BBD. A maximum degradation of 88.8% was achieved with the partially purified enzyme isolated from Pleurotus eryngii at 1µgmL-1 levofloxacin concentration which was at par with the commercial laccase which showed 89% degradation in synthetic wastewater at the optimized conditions. The biodegradation studies were conducted using only 2 units of laccase. Thus, the expensive commercial laccase can be effectively replaced by crude laccase isolated from indigenous macrofungi such as P. eryngii, P. florida and P. sajor caju as a cost effective alternative to degrade levofloxacin present in contaminated wastewater using as low as 2 units of enzyme for a 72h treatment period.

Removal of levofloxacin through adsorption and peroxymonosulfate activation using carbothermal reduction synthesized nZVI/carbon fiber

Nano zero-valent iron (nZVI) is widely used for decontamination. The main issues associated with nZVI are agglomeration and oxidation in the long term. In this study, the carbothermal reduction of cotton fiber was conducted for the synthesis of nZVI supported on cotton carbon fiber (nZVI/CF) to address the agglomeration and oxidation of nZVI. Synergistic adsorption and peroxymonosulfate (PMS) activation using nZVI/CF for removing levofloxacin (LEV) are reported herein. The nZVI concentration and morphology were conveniently adjusted by soaking cotton fiber in ferric nitrate solutions of various Fe3+ concentrations. The carbothermal reduction of the cotton fiber at 900 °C contributed to the reduction of Fe3+ into nZVI. A nZVI/CF-900-0.3 system was obtained through the carbothermal reduction of cotton fiber soaked in 0.3 M ferric nitrate. Favorable adsorption of nZVI/CF-900-0.3 to LEV facilitated LEV degradation under PMS activation. Approximately 93.83% of LEV (C0 = 20 ppm) was removed within 60 min with 0.2 g/L of the catalyst and 1 mM PMS. It was preferable to use nZVI + CF-900 to activate PMS for degrading LEV, thus confirming the favorable effect of LEV adsorption on further degradation. The nZVI/CF-900-0.3 exhibited excellent long-term stability given that it was able to activate PMS after it was stored for 6 months. ·SO4− played an important role in LEV degradation in the presence of PMS.

Removal of levofloxacin and ciprofloxacin from aqueous solutions and an economic evaluation using the electrocoagulation process‏

ABSTRACT For this research, the utilisation of electrocoagulation (EC) toremove theciprofloxacin (CIP) and levofloxacin (LVX) from aqueous solutions was examined. The effective removal efficiencies are 93.47% for CIP and 88.00% for LVX, under optimum conditions. The adsorption isotherm models with suitable mechanisms were applied to determine the elimination of CIP and LVX utilizingtheEC method. Thefindingsshowed the adsorption of CIP and LVX on iron hydroxide flocs followed the Sips isotherm, with correlation coefficient values (R2) of 0.939 and 0.937. Threekinetic models were reviewed to determine the accurate CIP and LVX elimination methods using the EC method. The results showed that itfittedfor the second-order model, which indicated that the chemical adsorption mechanism controlled the removal of CIP and LVX. The R2 with CIP is 0.944, and LVX is 0.941. For binary system removal, efficiencies were 93.00, 90.10, and 96.30% for CIP, and 91.80, 96.10, and 92.97% for LVX, at the CIP ratio: LVX of 1:1, 1:4, and 4:1. The electrode consumption (ELC) and electrical energy consumption (EEC) were found at 0.208 g and 3.21 kWh−3 for a single operation. The operating cost was estimated at 0.613 US$ m−3.

In situ fabrication of a novel S-scheme heterojunction photocatalyts Bi2O3/P-C3N4 to enhance levofloxacin removal from water

The removal of antibiotics from water by S-scheme heterojunction photocatalytic materials has become a research hotspot in recent years. Herein, an S -scheme heterojunction Bi2O3/P-C3N4 composite photocatalytic material was prepared via in situ thermal polymerization and the degradation effect and internal mechanism of levofloxacin (LVFX) were explored under simulated sunlight. The results show that the Bi2O3/P-C3N4 composite photocatalytic material can remove 89.2% of the LVFX in water within 75 min under simulated sunlight, which is greatly improved compared to the original Bi2O3 and P-C3N4. The degradation effect is improved because the constructed S-scheme system helps spatially separate the electrons with higher reducing abilities generated by P-C3N4 and the holes with higher oxidizing ability generated by Bi2O3; moreover, BET specific surface area and the hydrophilicity is improved. Further through radicals capture, electron spin resonance (ESR), the density functional theory (DFT) experiments verified the mechanism of S-scheme heterojunction degradation of LVFX and revealed that holes and superoxide free radicals are the main active substances in the degradation of LVFX. Finally, liquid chromatography–tandem mass spectrometry (LC–MS) was used to determine the intermediate products in the degradation path, and the LVFX degradation pathway was proposed. This study provides a new insight into the degradation of LVFX and provides support for antibiotic removal of photocatalytic materials in real water environments.

OPTIMIZATION OF LEVOFLOXACIN REMOVAL FROM AQUEOUS SOLUTION USING ELECTROCOAGULATION PROCESS BY RESPONSE SURFACE METHODOLOGY

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.

Anaerobic biodegradation of levofloxacin by enriched microbial consortia: Effect of electron acceptors and carbon source

For improving the understanding of anaerobic degradation mechanism of fluoroquinolone antibiotics (FQs), the degradation of a representative FQs, levofloxacin (LEV), by six enriched anaerobic consortia were explored in this study. The effect of sulfate and nitrate as the electron acceptor and glucose as the carbon source on LEV anaerobic degradation were investigated. Addition of glucose and nitrate alone deteriorated LEV removal from 36.5% to 32.7% and 29.1%, respectively. Addition of sulfate slightly improved LEV removal to 39.6%, while simultaneous addition of glucose and sulfate significantly enhanced LEV removal to 53.1%. Twelve biodegradation intermediates were identified, which indicated that cleavage of piperazine ring is prior to that of quinolone ring, and hydroxylation, defluorination, demethylation, and decarboxylation were the primary steps of LEV anaerobic degradation. Lactobacillus, unclassified _f_Enterobacteriaceae, and Bacillus were enriched by simultaneous addition of glucose and sulfate, with relative abundance of 63.5%, 32.7%, and 3.3%, respectively. The predicted high gene abundance of xenobiotics biodegradation & metabolism, carbohydrate metabolism, and assimilatory sulfate reduction in the consortium, indicated a co-metabolism between carbohydrate metabolism, sulfate metabolism, and LEV degradation under glucose and sulfate added condition. The study revealed that simultaneous addition of glucose and sulfate is the favorable condition for LEV anaerobic degradation.

Bioassay- and QSAR-based screening of toxic transformation products and their formation under chlorination treatment on levofloxacin

Levofloxacin (LEV) is a broad-spectrum quinolone antibiotic and widely used for human and veterinary treatment. Overuse of LEV leads to its frequent occurrence in the water environment. In this study, the transformation characteristics of LEV in water during the simulated chlorination disinfection treatment were explored. Fifteen major transformation products (TPs) of LEV were identified, and their plausible formation pathways were proposed. The reaction pathways were strongly dependent on pH condition, and LEV removal was relevant to free available chlorine (FAC) dose. Antibacterial activity of chlorination system was dramatically declined when FAC was more than 3-equivalent (eq) due to the elimination of antibacterial related functional groups. Genotoxicity of chlorination system increased more than 3 times at 0.5-eq of FAC and then decreased with increasing FAC dose, which were in accordance with the relative concentration of toxic TPs estimated by QSAR model. These results implied that the combination of bioassay, QSAR computation and chemical analysis would be an efficient method to screen toxic TPs under chlorination treatment. It is anticipated that the results of this study can provide reference for optimizing operational parameters for water disinfection treatment, and for scientifically evaluating the potential risk of quinolone antibiotics.

A novel graphene oxide decorated with halloysite nanotubes (HNTs/GO) composite used for the removal of levofloxacin and ciprofloxacin in a wide pH range

A novel HNTs/GO composite used for the removal of levofloxacin and ciprofloxacin in a wide pH range.

Facile synthesis of Fe3O4@MIL-100(Fe) towards enhancing photo-Fenton like degradation of levofloxacin via a synergistic effect between Fe3O4 and MIL-100(Fe)

The Fe3O4@MIL-100(Fe) hybrid composites are successfully synthesized via an in-situ growth method and characterized using various techniques. The ability of the magnetic metal–organic framework to promote photo-Fenton like processes is investigated using levofloxacin as a representative substrate. The results show that the composite with a Fe3O4:MIL-100(Fe) mass ratio of 1:4 has a higher degradation efficiency (up to 93.4%) than Fe3O4, MIL-100(Fe), and the other fabricated composites. This higher catalytic activity is ascribed to the synergistic effect between Fe3O4 and MIL-100(Fe), by which the quick separation of hole-electron pair from MIL-100(Fe) and the efficient reduction of Fe3+ to Fe2+ in the photo-Fenton reaction are mutually promoted. Moreover, the composite shows favorable recyclability without apparent loss of apparent photo-Fenton activity even after five cycles, and more importantly, can be recovered magnetically. The possible degradation mechanism and intermediates of levofloxacin in the photo-Fenton reaction have been tentatively proposed based on free radical quenching, electron paramagnetic resonance and mass spectrometry analysis. Finally, the developed Fe3O4@MIL-100(Fe) is successfully applied for the removal of levofloxacin from spiked wastewater with removal efficiencies ranging from 77.9 to 85.5%, which indicates that the proposed system has significant potential for wastewater treatment applications.

Efficient Removal of Levofloxacin by Activated Persulfate with Magnetic CuFe2O4/MMT-k10 Nanocomposite: Characterization, Response Surface Methodology, and Degradation Mechanism

In this study, a magnetic copper ferrite/montmorillonite-k10 nanocomposite (CuFe2O4/MMT-k10) was successfully fabricated by a simple sol-gel combustion method and was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunner–Emmett–Teller (BET) method, vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS). For levofloxacin (LVF) degradation, CuFe2O4/MMT-k10 was utilized to activate persulfate (PS). Due to the relative high adsorption capacity of CuFe2O4/MMT-k10, the adsorption feature was considered an enhancement of LVF degradation. In addition, the response surface methodology (RSM) model was established with the parameters of pH, temperature, PS dosage, and CuFe2O4/MMT-k10 dosage as the independent variables to obtain the optimal response for LVF degradation. In cycle experiments, we identified the good stability and reusability of CuFe2O4/MMT-k10. We proposed a potential mechanism of CuFe2O4/MMT-k10 activating PS through free radical quenching tests and XPS analysis. These results reveal that CuFe2O4/MMT-k10 nanocomposite could activate the persulfate, which is an efficient technique for LVF degradation in water.

Efficient removal of levofloxacin from different water matrices via simultaneous adsorption and photocatalysis using a magnetic Ag3PO4/rGO/CoFe2O4 catalyst

A magnetic Ag3PO4/rGO/CoFe2O4 ternary catalyst was firstly prepared and used for removing levofloxacin (LVF) from different water matrices via simultaneous adsorption and photocatalysis. Compared with Ag3PO4 and Ag3PO4/CoFe2O4, Ag3PO4/rGO/CoFe2O4 shows a superior adsorption-photocatalysis performance for LVF elimination since rGO component not only improves the adsorption ability but also enhances the charge separation efficiency of the catalyst. About 90.7% of LVF in distilled water (10 mg/L) was removed by the ternary catalyst after adsorption for 0.5 h and photocatalysis for 1.0 h, and the removal of LVF performed well in the pH range of 3.51–9.47. Singlet oxygen (1O2) was the major reactive oxygen species for LVF degradation in Ag3PO4/rGO/CoFe2O4 system under visible light, as confirmed by the quenching experiments and ESR study. Based on the detected intermediates in the photocatalytic process, the possible LVF degradation pathways were well-established. As-synthesized Ag3PO4/rGO/CoFe2O4 can also efficiently remove LVF from the different real water matrices (river water, lake water and secondary effluent) via simultaneous adsorption and photocatalysis. Moreover, magnetic Ag3PO4/rGO/CoFe2O4 can be easily recovered and effectively reused for the removal of LVF in actual water bodies.

One-Step Fabrication of Three Metals Zif and its Application for Adsorption of Levofloxacin in Aqueous Solution

Background: Zeolitic imidazolate frameworks with three metals Zn, Co and Ag (ZIF-3M) and ZIF-67 were synthesized at room temperature and characterized with different techniques such as FESEM, BET, EDX and XRD. Then, the synthesized nanoparticles were successfully applied for the removal of levofloxacin from aqueous solutions. Methods: To optimize the significant factors (i.e., pH, adsorbent dose and contact time), the response surface methodology (RSM) was implemented based on Box-Behnken design (BBD) in each step, an appropriate amount of adsorbent was added to 30 ppm of a solution containing levofloxacin and the pH was adjusted to the desired value with 0.1 M HCl or 0.1 M NaOH. The mixture was stirred at room temperature and then centrifuged at 7500 rpm for 3 min. Results: The optimal conditions for each variable were performed using Box-Behnken design. Results revealed that ZIF-3M nanoparticles more efficiently remove levofloxacin than ZIF-67 in aqueous solution. Conclusion: In this research, new three metals ZIF (ZIF-3M) nanoparticles were synthesized with Ag, Zn and Co in aqueous solution and characterized by different techniques. Results indicated successful synthesis with preserving ZIF framework. Results indicated that ZIF-3M has more ability for the removal of levofloxacin than ZIF-67. Isotherm studies showed that the most suitable model for the adsorption of levofloxacin onto ZIF-3M has a good agreement with the Langmuier model.

Enhanced decontamination of levofloxacin as toxic pharmaceutical residuals from water using CaO/MgO nanorods as a promising adsorbent

Novel MgO/CaO nanocomposite (MgO/CaO NRs) was synthesized by the hydrothermal method using diatomite porous frustules as a substrate under the microwave irradiation. The composite appeared as well crystalline rod-like nanoparticles with 52.3 nm as average particle size and 112.8 m2/g as BET surface area. The synthetic MgO/CaO NRs were addressed as a novel adsorbent for promising removal of levofloxacin (LVX) as pharmaceutical residuals. The adsorption studies revealed effective uptake of levofloxacin by MgO/CaO NRs with theoretical qmax of 106.7 mg/g and the equilibrium time of 720 min considering the best pH value (pH 7). The equilibrium studies highly fitted with the Langmuir model of monolayer adsorption considering the values of Chi-squared (χ2) and determination coefficient. The estimated adsorption energy from Dubinin–Radushkevich (0.2 kJ/mol) signifies physisorption mechanisms that might be coulombic attractive forces considering the kinetic studies. The thermodynamic addressing for the reactions verified their spontaneous and exothermic nature within a temperature range from 303 to 333 K. Additionally, the prepared MgO/CaO NRs show significant recyclability properties to be used in realistic remediation process and its uptake capacity is higher than several studied adsorbents in literature.

Effective Removal of Levofloxacin from Pharmaceutical Wastewater Using Synthesized Zinc Oxid, Graphen Oxid Nanoparticles Compared with their Combination

The presence of antibiotic traces in the aquatic system due to the inefficient treatment of the pharmaceutical wastewater represented threats, such as bioaccumulation and antibiotic-resistance, to the environment and human health. Accordingly, for the first time, the current work utilized the photocatalytic degradation and the adsorption approach for Levofloxacin (LEVO) in pharmaceutical wastewater using new designed nano aspects. Therefore, spherical Zinc oxide nanoparticles (ZnONP) sized 17 nm and ultrathin sheet-like structure graphene oxide nanosheets (GONS) with layer thickness ~5 nm were fabricated separately or in a combination between them then characterized via Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Fourier Transforms Infrared Spectroscopy (FTIR), absorption spectra (UV-Vis) and Brunauer-Emmett-Teller (BET). Additionally, several parameters were investigated to evaluate the potential of the removal process, such as pH, the exposure time to UV radiation, the type and concentration of the nanoparticles (NPs) and the initial concentration of the drug using a mixed fractional factorial design. The most effective parameter for LEVO removal was the NPs type followed by the initial drug concentration. Furthermore, an RP-HPLC/UV method was developed and validated for measuring the percentage of removal for LEVO drug. The highest percentage removal for both 50 and 400 µg mL−1 LEVO was 99.2% and 99.6%, respectively, which was achieved using ZnONP/GONS combination at pH 9 ± 0.05 and UV light exposure time 120 min. In addition, the negative antibacterial activity of the treated wastewater sample confirmed the drug removal. The established protocol was successfully applied on wastewater samples collected from a pharmaceutical company that encouraged researchers to mainstream this design to be applied on other pharmaceutical wastewater drugs.

One-pot synthesis of magnetic CuO/Fe2O3/CuFe2O4 nanocomposite to activate persulfate for levofloxacin removal: Investigation of efficiency, mechanism and degradation route

A cost-effective one-pot hydrothermal route was used to prepare novel magnetic CuO/Fe2O3/CuFe2O4 nanocomposites activating persulfate (PS) to remove levofloxacin from water. The optimized CuO/Fe2O3/CuFe2O4 sample (denoted as CuFeO-2) possessed a higher catalytic performance for levofloxacin degradation by activating PS than those of CuO, Fe2O3, CuFe2O4 and recently reported heterogeneous catalysts. After 120 min, the degradation efficiency and the mineralization degree of levofloxacin (10 mg∙L−1) in CuFeO-2/PS system reached 75.5% and 64.5%, respectively. The influence of some significant reaction parameters (e.g., PS dosage, catalyst dosage, initial pH, temperature and coexisting inorganic anions) on levofloxacin removal in CuFeO-2/PS system was studied and analyzed. Although the catalytic activity of magnetic CuFeO-2 slightly declined after each cycle due to the loss of active Cu(II), the recyclability of CuFeO-2 was significantly better than that of CuO. The trapping experiments and ESR studies confirmed that singlet oxygen (1O2), sulfate radical (SO4•−) and hydroxyl radical (•OH) were generated in CuFeO-2/PS system, thus, the degradation of levofloxacin can be achieved via the non-radical and radical oxidation processes. The role of copper, iron and oxygen elements in CuFeO-2 on PS activation was investigated by ART-FTIR and XPS. The possible degradation routes of levofloxacin were put forward according to the detected intermediate products. Moreover, the performance of CuFeO-2/PS system for levofloxacin degradation in real water matrix was also investigated.