Degradation Of Ciprofloxacin Research Articles

Pig manure biochar in soil forms catalytic system with endogenous H2O2 to degrade ciprofloxacin in purple soil

Biochar might improve ciprofloxacin (CIP) removal in soil, but little was known about how it goes on in purple soil. Thus, we investigated the variations of CIP in soil amended with pig manure (PM) derived biochar generated at 300℃ and 600℃ (PMC3 and PMC6). Compared with CK, PM, PMC3 and PMC6 decreased residual CIP by 42.3%, 48.8%, and 46.1%, respectively, confirming the enhancement of PM, PMC3 and PMC6 on CIP dissipation and indicating a higher performance of PMC3 and PMC6 in CIP removal than that of PM. Signal of persistent free radicals (PFRs) was observed in PMC3 and PMC6, which was contributed to the formation of O2·- and H2O2. Compared to PM, the secretion of H2O2 by microbe in PMC3 and PMC6 were enhanced by 71.5%-97.5% and 57.4%-79.5%, respectively. Meanwhile, catalase contents in PMC3 and PMC6 were reduced by 18.7%-68.6% and 8.4%-59.7%, respectively. These results suggested that H2O2 accumulated much easily in PMC3 and PMC6 than that in CK, which was benefited to the ·OH formation through the reaction between H2O2 and PFRs. Pearson correlation analysis identified that ·OH was the major contributor for 72.2%-80.2% of CIP removal in soil. In addition, degradation products were identified using UPLC-Q-TOF analysis. The results showed that the quinolone ring and piperazinyl ring were the main CIP degradation products. Under the action of ·OH, the piperazinyl ring in the CIP was completely destroyed. The phytotoxicity analysis was evaluated by bioreporter and Estimation Programs Interface (EPI) Suite. This study implies that biochar is a useful material for controlling CIP contamination through forming catalytic system with endogenous H2O2. These process insights have important implications for the pathway for CIP dissipation by biochar.

Boosting ciprofloxacin and indigo carmine dye photodegradation using S-scheme plate-like BiOI@sulfated TiO2 heterojunctions: An understanding of the performance, the degradation route, and DFT computation

Sustainable BiOI/sulfated TiO2 nanocomposites were created for the present study utilizing the environmentally friendly dispersion-ultrasonication technique. Then, their ability to degrade the medication ciprofloxacin (CIP) and indigo carmine coloring (IC) in aquatic water was evaluated. The optimized catalyst 10%BiOI/ST, denoted as 10BOST together with 5BOST, is subjected to thorough characterization together with that of sulfate-free TiO2 (10BOT) to assess their physiochemical, morphological, textural, structural, and elemental composition properties. It is noteworthy that the 10BOST composite achieves remarkable degradation and performs exceptionally well in photocatalytic IC and CIP degradation. In 35 min, it degrades IC to 100%, with a rate constant of 0.066 min−1, which is superior to that of 10BOT (0.054 min−1) in the incidence of visible light and without an oxidizing agent. In CIP, 10BOST yields 85.6% degradation with a rate constant of 0.027 min−1 preceding 0.024 min−1 for 10BOT when potassium persulfate oxidizing agent is present. This exceptional performance is ascribed to the composite's diminished particle diameter, largest pore radius, hydrophilicity, improved light absorption, and the developed heterojunction between ST and BiOI, as demonstrated by XPS, TEM, XRD, EDX and IR data. The effect of sulfation concentration, pH, Ti3+/Ti4+ ratio, and pollutant concentration were studied together with the active species determinations, which revealed that active radicals like SO4•−, •OH, and h+ were well participated in the pollutant's decomposition. Testing for toxicity shows that during CIP breakdown, innocuous hazardous intermediates evolve with a notable 70% mineralization rate in their TOC. Furthermore, 10BOST showed strong stability and reusability. Using DFT simulations, profound insights into the principles underlying the adsorption sites of pollutants, their chemical reactivity, and the arrangement of their electrical charges, and how these factors affect the reaction mechanism on BOST photocatalysts.

Novel insights into revealing the intrinsic degradation mechanism of ciprofloxacin by Chlorella sorokiniana: Removal efficiency, pathways and metabolism

Microalgae-mediated biodegradation of antibiotics has attracted increasing interest. However, the exact degradation mechanism behind it remains elusive, which is crucial for improving its efficiency and large-scale implementation. Therefore, this study aims to thoroughly investigate how Chlorella sorokiniana (C.sorokiniana) degrades ciprofloxacin (CIP) from the molecular level to elucidate its complicated degradation mechanism. Results show that C.sorokiniana exhibited an impressive removal rate of 38.05–74.29 % for CIP, the synergistic effect of biosorption and biodegradation was the main removal mechanism of CIP. The content of EPS increased by 11.84–103.31 %, acting as a carrier to increase the bioavailability of CIP. Enzyme activity analysis identified POD, CYP450, and GST as the major catalytic enzymes responsible for the biotransformation process of CIP with increases of 6–41.2 %, 18.78–102.1 % and 3.53–58.15 %, respectively. Molecular docking further revealed that the binding affinity of 146.24 μM, 27.71 μM and 16.33 μM was observed for POD,CYP450, and GST, respectively, indicating the high metabolic efficiency of CIP by CYP450. Finally, DFT calculations elucidated the enzyme-mediated biodegradation pathway of CIP, including hydroxylation, decarboxylation, and ring opening. These findings are expected to further fill the knowledge gap on the catalysis mechanism of CIP degradation by enzymes and improve the practical application of microalgae to antibiotic wastewater.

Degradation of ciprofloxacin by hydrogen peroxide activated with pyrite under simulated sunlight

Ciprofloxacin (CIP) residues in the environment pose risks to both human health and ecosystems. In this study, we explored the effect of hydrogen peroxide (H2O2) on CIP degradation, activated by pyrite (FeS2) under simulated sunlight. XRD, XRF, EDS, XSP, DRS, and PL tests confirmed the high purity of FeS2 and its photocatalytic properties. With [CIP] = 30 μM, [FeS2] = 0.2 g/L, [H2O2] = 0.2 mM, CIP removal reached 87.6 %. The removal rate of TOC reached 55.3 % after 60 min of light exposure, and hydroxyl radicals (OH) contributed 72.7 % to the process. H2O2 utilization was 67.5 %, and the system operated effectively across a pH range of 2.00 to 8.00. CIP removal in river water reached 87.9 % after 3 h of light exposure, though the degradation was slower than in ultrapure water. Cl−, SO42−, and NO3− had little effect on degradation, whereas H2PO4−, CO32−, and HCO3− significantly inhibited the process as their concentrations increased. In livestock wastewater, the simulated sunlight-FeS2/H2O2 system was less effective, but after diluting the wastewater 100 times, CIP removal reached 87.6 % after 60 min. The degraded solutions showed no significant toxicity. These findings suggest that FeS2, combined with simulated sunlight, can effectively catalyze low concentrations of H2O2 to produce OH radicals, removing antibiotics from livestock wastewater.

Symmetry-Engineered BINOL-Based Porous Aromatic Frameworks for H2O2 Production via Artificial Photosynthesis and In Situ Degradation of Pharmaceutical Pollutants.

Accomplishing visible light-driven H2O2 production at millimolar concentrations is practically challenging, particularly for organic semiconductors. In this context, achieving a maximum H2O2 production rate of 31.60 mmol·g-1·h-1 by using porous aromatic frameworks (PAFs) represents a significant accomplishment. We report the unusual photoactivity of tetraphenylmethane-BINOL-linked PAFs in triplet oxygen activation to facilitate the generation of reactive oxygen species (ROS), as confirmed by their optical and electrochemical responses, despite the absence of a conventional chromophoric moiety. Moreover, an in situ BINOL formation strategy was used to synthesize these PAFs during polymerization in contrast to the reported protocols involving chiral BINOLs as precursors. The as-synthesized polymers had a capsule-like morphology (for TPM-BINOL-6), high thermal stability up to 348 °C, and a high Brunauer-Emmett-Teller (BET) surface area of up to 1382 m2/g (for TPM-BINOL-4). Interestingly, they showed sunlight-driven production of H2O2 via an oxygen reduction reaction of up to 17.05 mmol·g-1·h-1 in 1:10 isopropanol in water for TPM-BINOL-6, which was quantified by titration with ceric sulfate. It also exhibited exemplary photocatalytic efficiency with an H2O2 production rate of 6.65 mmol·g-1·h-1 in seawater. Interestingly, the H2O2 production rate reached a maximum of 18.03 mmol·g-1·h-1 with an SCC efficiency of 4.5% under an AM 1.5G solar simulator and apparent quantum yield (AQY) of 15.8% (at λ = 456 nm) for TPM-BINOL-6 in ethanol:water = 1:10. Moreover, the exceptionally high H2O2 production rate of 31.60 mmol·g-1·h-1 was achieved in 1:1 ethanol in water under 50 W blue LED light. Furthermore, these PAFs generated adequate ROS, which were utilized in the photocatalytic degradation of tetracycline via the superoxide intermediate. Additionally, the as-formed H2O2 was further channelized in the pollution abatement catalytic system for the fast degradation of ciprofloxacin (within 4 h) and the reduction of toxic oxometallate Cr(VI) within 10 min, which is one of the earliest reports of utilizing photosynthesized H2O2 for environmental detoxification.

Dual-active-group co-modification of BiOBr for boosting photocatalytic CO2 reduction coupled with ciprofloxacin oxidation

Coupling CO2 photoreduction with ciprofloxacin (CIP) oxidation presents a promising strategy for achieving not only the complete utilization of photoexcited carriers but also the win–win goals of energy conversion and environmental remediation. In this study, we utilized an aminated BiOBr catalyst with surface hydroxyl groups (NH2/BOB–OH) for efficient photocatalytic CO2 reduction coupled with CIP oxidation. In this process, hydroxyl (OH) and amino groups (NH2) adsorbed and activated CIP (an organic pollutant) and CO2 molecules, respectively, promoting the overall photocatalytic redox activity. Remarkably, 0.5NH2/BOB–OH exhibited excellent photocatalytic redox performance for CO2 reduction coupled with CIP oxidation, with the CO yield and CIP degradation efficiency being 6.85 and 1.08 times higher, respectively, than those achieved using BiOBr without any active groups. Moreover, a series of in situ experimental characterizations and theoretical simulations revealed that these two opposing active groups not only accelerated carrier separation but also boosted the surface reactivity of the catalyst. These findings provide helpful insights into the dual-active-group functionalization of semiconductors, leading to their high photoredox activity for energy conversion along with environmental remediation.

Co-N3 site activated peroxymonosulfate for rapid degradation of ciprofloxacin: Synergistic effect of free radicals and nonfree radicals

Nitrogen-doped metal-organic framework (MOFs)-derived carbon materials (denoted as Co-MOF-74@N-T-x) were successfully fabricated by calcinating Co-MOF-74, utilizing the green precursor of melamine. Among these materials, Co-MOF-74@N-500-2 demonstrated superior catalytic performance in activating peroxymonosulfate (PMS), achieving over 95 % degradation of ciprofloxacin (CIP) within 15 min, with a rate constant that was 1.25 times greater than that of Co-MOF-74-500. The primary active species identified in this study were sulfate radicals (SO4•−) and singlet oxygen (1O2), with the latter playing an important role in the degradation of CIP in the Co-MOF-74@N-500-2/PMS system. Theoretical calculations confirmed that the enhanced catalytic activity primarily stemmed from the Co-N3 configuration, which was more effective in activating PMS than the other configurations were. Co-MOF-74@N-500-2/PMS showed excellent performance in oxidizing CIP across a broad pH range (3.0–9.0) and demonstrated stability over five cycles, along with impressive degradation performance capabilities for a wide range of pollutants including metronidazole (MNZ), oxytetracycline (OTC), nitrofurantoin (FNT), methylene blue (MB), and acid orange (OG). This study presents a viable strategy for developing efficient and durable catalytic systems aimed at degrading organic pollutants via PMS.

Photodegradation of ciprofloxacin and its interaction with Cu(II) in different water matrices: Insight into degradation pathways

Co-contamination of ciprofloxacin (CIP) and Cu(II) is common in marine aquaculture water. However, the transmission and transformation of these substances in natural water matrices are often overlooked. This study sought to assess the impact of Cu(II) on CIP degradation in distilled (DI) and simulated (SI) mariculture water, as well as to develop a relationship between Cu(II), CIP, and its degradation products. First, complexation assays and analog computations revealed that Cu (II) forms complexes by binding to the oxygen atoms of the carbonyl (C=O) and carboxyl (COOH) groups in the CIP molecule. Second, photodegradation experiments showed that Cu(II) significantly hindered the degradation effect of CIP in DI water, while Cu(II) did not significantly hinder the degradation of CIP in SI water. Furthermore, the effect of Cu(II) on the degradation mechanism of CIP was determined by combining quenching and EPR experiments, Materials Studio software calculations, and UPLC-MS results. It was demonstrated that Cu(II) enhanced the production of singlet oxygen (1O2), hydroxyl radicals (•OH), and superoxide radicals (•O2−) in DI water. In the presence of Cu(II), CIP undergoes hydroxylation and decarbonylation reactions, forming hydroxylated and nitroxylated products. Additionally, direct defluorination and cleavage of the piperazine ring occur, followed by complexation reactions with Cu(II). However, in SI water, the production of 1O2 depends on the indirect action of Cu(II) and the excited state transformation of organic matter. Experimental evidence has shown that CIP can create intermediate compounds that include O-O peroxide rings, with or without the presence of Cu(II). When Cu(II) is present, the cyclopropyl group of the CIP molecule is more prone to transformation and so degradation. Finally, the toxicity assessment results indicated that both Cu(II) and SI water increased the toxicity of the degradation products.

Charge separation by switching heterojunction system from Type-II to S-scheme for enhanced photocatalytic activity: Environmental detoxification and H2 production

The development of highly efficient photocatalysts is essential for harnessing solar energy for pollutant degradation and hydrogen (H2) production. This study provides a novel ternary S-scheme photocatalyst (Fe2O3/Bi2O3/g-C3N4), prepared from optimized binary 20-Bi-C via a simple electrostatic self-assembly method for the first time. Using various methods including UV–vis DRS, PL, ESR, photocurrent, Mott-Schottky, XPS, XRD, FTIR, SEM, TEM, and BET, the optical, structural, and morphological characteristics of the produced materials were fully studied. The photocatalytic performance of as-manufactured materials was evaluated through the degradation of the Ciprofloxacin (CIP) and H2 production. Under optimized conditions determined by the RSM method, a maximum CIP degradation of 97.20 % was achieved at a rate of 0.053 min−1, with the catalyst dosage: 0.44 g/l, CIP concentration: 26.07 mg/l, pH: 6.29 and Time: 63.01. The optimized heterojunction exhibited an exceptional photocatalytic H2 generation rate of 2428 μmol·g−1·h−1 within 2 h, surpassing the binary 20-Bi-C photocatalyst by 1.3 times. Furthermore, after five continuous cycles, the 5-Fe2O3/Bi-C photocatalyst showed good chemical stability and reusability, sustaining a degradation rate of over 96 % and a TOC removal of 80 %. Experiments on the identification of free radicals have demonstrated the important roles that O2−, h+, and OH species play in the photocatalytic process. The enhancement mechanism of 5-Fe2O3/Bi-C involves the successful synthesis of Fe2O3/Bi-C photocatalyst with well-aligned positions of band gap edges, enabling the facile charge transfer through S-Scheme mechanism. Furthermore, the study investigates the impact of environmental factors, including solution pH, water matrices, and the efficiency of the synthesized photocatalyst on other organic pollutants. The photocatalytic degradation behavior of CIP is predicted using LC-MS analysis. This work provides a new method for building S-scheme heterojunctions by creatively converting the type-II heterojunction system to an S-scheme by metal oxide doping.

Layered bismuthene forming the interfacial pathway for rapid charge transfer in CuNb13O33/g-C3N5 photocatalyst for enhancing ciprofloxacin degradation

The objective of the present research was to examine the usefulness of the photocatalytic degradation process in removing the ciprofloxacin drug from wastewater, which is difficult to remove from waterbodies. To tackle this difficulty, a ternary copper niobium oxide/carbon nitride/layered bismuthene heterostructure (CuNb13O33/g-C3N5-L-Bi) composite was developed by an intuitive solvothermal process. layered bismuthene (L-Bi) was prepared using a unique ball milling approach. According to the results of the characterization, adding L-Bi and g-C3N5 with a low band gap to the original band structure of CuNb13O33 makes it more efficient. After 120 min of irradiation, the modified CuNb13O33/g-C3N5-L-Bi sample significantly improved ciprofloxacin degradation, resulting in a degradation rate of 98 %. In addition, the impact of the catalyst that has been created on the removal of ciprofloxacin at various pH, catalyst dosages, and scavengers was also examined, demonstrating the catalyst’s suitability for purifying natural water environments. A detailed study of the steps used to break down ciprofloxacin has shown that many active species are involved, with a focus on the important roles played by reactive oxidative species (ROS). Thus, this study introduces a novel combination of layered bismuthene photocatalysts for environmentally friendly degradation of antibiotics.

Fabrication of boron modified bi-functional air diffusion electrode for ciprofloxacin degradation: In-situ H2O2 generation and self-activation

In order to improve H2O2 in-situ generation in electrochemical system, a boron (B) modified air diffusion electrode (B@ADE) was fabricated in the present study. Carbon black (CB) doped by B was deposited on ADE surface as catalytic layer. Performance of B@ADE with different B/C mass ratios has been investigated and 0.3 was identified as the optimal one·H2O2 yield can be achieved 204.85 mg L-1 within 45 min at 0.3-B@ADE, which was 1.51 times for that of ADE. Meanwhile, H2O2 self-activation on B@ADE surface was observed and effects of different operating parameters on •OH formation have been analyzed. XPS analyzation demonstrated that BC2O, BC2O and C=O/O-C=O were related to H2O2 generation. DFT calculation revealed that BCO2 was benefit for O2 adsorption, while BC2O promoted *OOH desorption with lower free energy barriers for H2O2 and •OH generation. Quenching experiments for ciprofloxacin (CIP) demonstrated that •OH, O2•- and 1O2 were co-existed in the system with their contribution quantified. Four possible degradation pathways were proposed through active sites identification by DFT calculation and intermediates detection by HPLC-MS/MS. Bio-toxicity analyzation results showed that the toxicity of most intermediates was lowered than CIP. These results proved that electrochemical oxidation system with B@ADE enhanced in-situ H2O2 generation and self-activation, with great potential for practical application.

Photocatalytic degradation of acetaminophen, ciprofloxacin and amoxicillin using UV/ZnO in a suspended photocatalytic reactor

Abstract This study aims at evaluation of the photocatalytic degradation of pharmaceutical compounds acetaminophen (ATM), ciprofloxacin (CXN), and amoxicillin (AMX) using zinc oxide (ZnO) nano powder as a photocatalyst in a suspended reactor using a 16 W UV lamp. Operating parameters pH, catalyst dosage, and pollutant concentration were optimised for a working volume of 1.3 litres of model pharmaceutical compounds. The photo degradation efficiency was 95% at pH 6 after 5 h of irradiation for ATM, 98% at pH 6 after 2 h of irradiation for CXN, and 100% at pH 10 after 3 h of irradiation for AMX. The reaction kinetics for the degradation of ATM, CXN, and AMX followed pseudo-first order with the rate constants in the order of kAMX>kCXN>kATM 0.0321 min−1, 0.0232 min−1 and 0.0070 min−1 respectively. TOC (Total Organic Carbon) analysis was carried out for the model compounds, among which compound amoxicillin was found having a higher rate constant of about 0.0108 min−1, which is 1.2 times higher than ciprofloxacin and 2.5 times greater than acetaminophen. This study concludes that ZnO nano powder is efficient in degrading the model pharmaceutical compounds ATM, CXN, and AMX by utilising the UV light, which is evident from the results of the UV–vis spectrophotometer, HPLC analysis, and mineralisation study. In addition, ANOVA was performed on the results obtained from optimisation studies, which confirms the substantial influence of the operating parameters on the degradation of the compounds.

Visible Light-driven Effective Photocatalytic Degradation of the Persistent Organic Pollutant Using Cobalt-doped Strontium Titanate

Residual antibiotics in natural aquatic environments pose a critical threat to humans and other organisms. However, most sewage treatment plants fail to remove them. Photocatalytic nanomaterials can efficiently destroy these persistent organic pollutants in wastewater. In this study, we developed a series of cobalt-doped SrTiO3 (Co-STO) catalysts with different doping amounts (3, 5, 7, and 9 wt%) for the effective photocatalytic degradation of ciprofloxacin (CIP). The nanostructures were characterized using X-ray diffraction, field-emission scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-visible diffuse reflectance spectroscopy, and Brunauer–Emmett–Teller N2 adsorption isotherms. The Co-STO particles have a mesoporous diameter of ~30.8 nm, and the Co-doped nanostructures have a rhombohedral hopper-like shape. Co-doping decreased the bandgap of pure STO from 3.61 to 3.42 eV, which enabled it to absorb visible light. Among the catalysts, 7 wt% Co-STO showed the highest CIP degradation activity (90.6%) during 120 min of visible-light irradiation. Radical scavenging experiments revealed that superoxide (O2 •-) is the primary reactive species during degradation. These Co-doped nanostructures have potential applications in the remediation of hazardous pollutants in pharmaceutical wastewater. Moreover, the crystal and energy band structure, density of states, and Bader charge of these molecules were analyzed.

Boosting charge separation and active sites exposure by hollow S-scheme MoSe2/Fe2O3 heterojunction for enhanced photocatalytic peroxymonosulfate activation towards ciprofloxacin removal

Regulating the properties of heterogeneous catalyst for efficient peroxymonosulfate (PMS) activation to pollutants degradation remains a challenge in photo-assisted Fenton-like reaction (PF) system. In this study, the novel S-scheme MoSe2/Fe2O3 (H-FMS) heterojunction with hollow nanostructure was successfully developed as visible-light-driven PMS activator for removal of ciprofloxacin (CIP). The prepared H-FMS catalyst in PMS/H-FMS/light system exhibits outstanding photocatalytic performance for CIP degradation, achieving 95.92 % removal of 5 mg/L CIP in 30 min with 0.5 mM PMS. The construction of S-scheme heterojunction provides photoinduced carriers with longer lifetime and higher redox abilities, thus sufficient photogenerated carriers are supplied to directly activate PMS. Simultaneously, the hollow nanostructure possessing multiple light reflection and scattering behaviors further facilitates the utilization of visible light. More importantly, high concentration of photoinduced electrons with high reduction ability in MoSe2 is conducive to continuous exposure of Mo4+ active sites for PMS activation through cycling between transition metal valence states. Overall, effectively separated electron-hole pairs and continuously exposed transition metal active sites both contribute to efficient activation of PMS as well as multi-path generation of ROS, leading to significant improvement in CIP degradation. The results of quenching experiment, electron spin resonance (ESR) technology, liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT) calculation confirm that both free radicals (SO4∙-, •OH and O2∙-) and non radicals (1O2 and h+) attack the active sites of CIP possessing high Fukui index, thus contributing to CIP degradation. This work would provide a novel insight for future development and application of photocatalytic PMS activation catalysts in water remediation.

Magnetic recyclable carboxymethyl cellulose/gelatin/citrate@Fe3O4 photo-nanocomposite beads for ciprofloxacin removal via hybrid adsorption/photocatalysis process under solar light as a renewable energy source

Magnetically separable cross-linked carboxymethyl cellulose/gelatin/citrate-functionalized magnetite nanoparticles (Cit-Fe3O4) photo-nanocomposite beads (mCMC/Ge) were synthesized and applied in synergistic adsorption/photocatalytic degradation of ciprofloxacin (Cipro) pharmaceutical pollutant under sunlight irradiation. Various analytical techniques were employed to characterize their structural, textural, magnetic, thermal, and optical properties. The removal efficiency of mCMC/Ge beads was investigated considering different influencing parameters (pH, beads dosage, contact time, Cipro concentration, and temperature). Experimental data modeling indicated that the adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models, with a maximum Langmuir adsorption capacity (qm) of 50 mg g−1 for mCMC/Ge, twice that of the matrix. Photocatalytic activity results showed prominent enhancement in Cipro removal using 1 g L−1 of mCMC/Ge at pH 7, as compared to Cit-Fe3O4, reaching 96 %, 85 %, and 63 % after 180 min of adsorption and 120 min of irradiation for initial pollutant concentrations of 10, 20, and 60 mg L−1, respectively. Furthermore, mCMC/Ge demonstrated efficient removal even in real water sample.The excellent removal performance of mCMC/Ge highlighted the synergy between polymeric matrix template and encapsulated Cit-Fe3O4 in improving Cipro adsorption and photodegradation. Furthermore, facile recyclability and sustained activity over five cycles identify mCMC/Ge photo-nanocomposite as a promising material for removing organic pollutants from contaminated waters.

Ag QDs modified BiOCl/UiO-66-NH2 Z-scheme heterojunction for accelerated visible light-driven photocatalytic degradation of ciprofloxacin

Ag quantum dots (QDs) anchored on the surface of BiOCl/UiO-66-NH2 Z-scheme heterojunctions were synthesized and characterized by various techniques such as X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV–vis DRS), electrochemical impedance spectroscopy (EIS), and photoluminescence (PL). The effects of Ag QDs loading, pH values and co-existing anions on the photocatalytic performance were comprehensively analyzed. The results concluded that the Ag QDs modified catalysts exhibited excellent photocatalytic performance for the degradation of ciprofloxacin (CIP), especially, the catalyst with 5 % Ag QDs loading (referred to as ABU-5) achieved a degradation efficiency of 72 % within 120 min and the apparent reaction rate constant was 0.00538 min−1. The outstanding performance of the ABU-5 catalyst is attributed to the introduction of Ag QDs as electron transfer bridges, improving visible light absorption and enhancing charge transfer between BiOCl and UiO-66-NH2. Free radical trapping experiments and leaching tests were carried out to determine the contribution rates of reactive species to the degradation efficiency and the concentration of Ag+ in solution after the reaction. The possible degradation pathways of CIP by ABU-5 were investigated by gas chromatography-mass spectrometry (GC-MS).

Efficient degradation of ciprofloxacin by innovative VUV/BN system: Kinetics, mechanism and toxicity assessment

Given the increasing emergence of widespread fluoroquinolones (FQs) in natural water environments and the limitations of traditional vacuum ultraviolet (VUV) systems for water decontamination, an innovative VUV/BN system was developed for the degradation and detoxification of ciprofloxacin (CIP) in this work. Unlike the VUV system, which primarily relies on hydroxyl radicals (·OH), the VUV/BN system significantly enhances the concentration of singlet molecular oxygen (1O2) to target the piperazine ring of CIP, achieving a defluorination efficiency of 98.88 % within 60 min. The degradation rate constant for CIP was found to be 2.76 times greater than that of the traditional VUV system. Additionally, varying concentrations of reactive species (RSs) in the VUV and VUV/BN systems resulted in distinct CIP degradation pathways. Due to the high selective oxidation capacity and environmental compatibility of 1O2, the VUV/BN system demonstrated excellent adaptability to environmental factors, maintaining stable operation in complex water matrices. Furthermore, the system exhibited high degradation capacity for CIP even in the fifth cycle, confirming its exceptional stability and reusability. The economic feasibility of the VUV/BN system was confirmed by its low electrical energy per order (EEO). This study underscores the potential of VUV/BN systems and enhances the understanding of CIP photodegradation.

Piezoelectric Energy Harvesting in Poly(vinylidene Fluoride‐co‐hexafluoropropylene)/Barium Titanate Nanofibers and Ultrasonic Assisted Piezocatalytic Degradation of Ciprofloxacin

AbstractAn innovative approach has been adopted through the synthesis of a cost‐effective ferroelectric host polymer, which was integrated with Barium Titanate (BaTiO3) to develop an efficient electrospun Polyvinylidene Fluoride‐Hexafluoropropylene/BaTiO3 (PVdF‐HFP/BaTiO3) nanocomposite (PBT), designated for energy harvesting and piezocatalytic applications. FT‐IR affirmed the existence of the crystalline β‐phase within the nanofibers. SEM images showed that nanofiber diameter decreases as applied voltage is increased in electrospinning. The BaTiO3 nanoparticles were scattered evenly in PBT, but at lower voltages, they aggregate. PBT showed enhanced piezoelectric performance under higher voltage conditions, registering a maximum piezoelectric output of ~7.7 V and an output current of 0.77 μA. Moreover, the composite exhibited a power density of 14.15 mW/m2 at a load resistance of 20 MΩ. Fabricated piezoelectric nanogenerator (PENG) demonstrated practical utility in flexible electronics, notably in charging capacitors of 0.47 μF and 1 μF. Additionally, the piezocatalytic degradation of the antibiotic ciprofloxacin (CIP) was effectively achieved using the electrospun nanofibers, with an impressive degradation rate of up to 99.6 % within 30 minutes under acidic conditions, and the material displayed notable reusability, maintaining up to 95.5 % efficiency after five cycles. DFT calculations and COMSOL simulations alongside a comparative examination of the electronic properties of PBT.

Effective degradation of ciprofloxacin from aqueous solutions using heterogeneous electro-Fenton coupled with Fe@Fe2O3 core-shell nanoparticle

In the current research, a Ti/RuO2 anode and Fe@Fe2O3 catalyst were synthesized for electro-Fenton (EF) removal of ciprofloxacin (CIP). The results of the ANOVA from response surface methodology (RSM) indicated a significant relationship between experimental and predicted values. 100% CIP and 45% total organic carbon (TOC) removal were predicted at pH of 8.83, time of 14.80min, current density of 19.19mA/cm2, pollutant concentration of 15.13mg/L, and catalyst dosage of 199.03mg/L. Among the operational parameters, current density (F value = 191.90) and catalyst dosage (F value= 5.79) had the greatest and least effect on the CIP removal rate, respectively. The stability tests revealed excellent reusability of electrodes for long-term decomposition of CIP. The BOD5/TOC > 0.6 in the treated solution confirmed acceptable performance of the heterogeneous EF process in CIP degradation. A 25% growth inhibition rate of plant stems in the treated solution demonstrated the low toxicity and biodegradability of the effluent. The efficiency of the heterogeneous EF process for CIP removal in water matrices ranged from 43.65% to 100%. By evaluating the parameters, mineralization, production of different radicals, and energy consumption, the heterogeneous EF process can be considered for the effective decomposition of CIP from aqueous environments.

Ciprofloxacin degradation over Co3O4 catalysts by the microwave-assisted persulfate oxidation: a critical role of coordination composition

The combination of catalysts and microwave (MW) effects presents an emerging approach for persulfate (PS) activation, while the effect of active sites of catalysts on the synergistic reaction remains poorly understood. Here, we regulated the coordination composition of Co3O4 by strategically controlling the oxygen atmosphere during fabrication. We found that Co3+ and Co2+ acted as reactive centers for microwave absorption and catalytic activation of persulfate, respectively. By altering the ratio between Co3+ and Co2+, we explored the Co3O4 (2.23)-550 catalysts with significantly improved synergistic activity for degrading ciprofloxacin (CIP), which was 33.0 and 26.8 times higher than PS- Co3O4 (2.23)-550 (without microwave) and MW- Co3O4 (2.23)-550 (without persulfate), respectively. Meanwhile, Co3O4 (2.23)-550 catalyst (0.5mgL-1) showed the highest degradation rate of CIP 92.6% (0.5mgL-1) within 10min under microwave. According to the radical identification and intermediate analysis, the efficient degradation of CIP was ascribed to both free radical and non-free radical pathways. Thus, this work raises new insights into the structure-activity relationship of catalysts, and provides an efficient way to eliminate antibiotics via synergistic catalysis.