Degradation Of Chloramphenicol Research Articles

Stabilize the oxygen vacancies in ZnO via altering local electronic structure by Co and Ni doping: A novel strategy for achieving durable visible light driven photo-Fenton degradation of chloramphenicol

The build-up of antibiotics, harmful pollutants, and pharmaceutical products has led to the significant contamination of environmental water bodies. Hence, the advancement of oxidation methods such as light-induced photo-Fenton degradation has proven crucial for efficiently desolating these harmful pollutants. Herein, we report a novel photo Fenton catalyst, Co and Ni co-doped ZnO (Zn1-x-yCoxNiyO) nanorods (NRs) for enhanced photocatalytic degradation of chloramphenicol (CAP) under visible light irradiation. The NRs were synthesized via the ultrasonication-assisted solvothermal method. Among the different Co and Ni doping concentrations, Zn0.96Co0.03Ni0.01O NRs showed superior photodegradation efficiency of 94.2%. Here, •OH radicals were identified as predominant reactive oxygen species in photocatalytic degradation by electron spin resonance (ESR) analysis and scavenging assay. The effect of various environmental parameters such as nanoparticle dosage, CAP concentration, pH, and ions were investigated to understand the impact of these parameters on the degradation of CAP. Further, Zn0.96Co0.03Ni0.01O NRs were stable for six consecutive photodegradation cycles, which showed their excellent efficiency and reusability for prolonged usage. Photostability was further confirmed by XPS and XRD analysis of the used photocatalyst. Also, the photodegradation pathway of CAP was predicted by identifying the intermediate compounds via GC-MS analysis. This approach holds promise for the efficient visible-light-driven degradation of pharmaceutical pollutants including CAP and contributes to the advancement of sustainable water treatment technologies.

Comprehensive analysis of biotransformation pathways and products of chloramphenicol by Raoultella Ornithinolytica CT3: Pathway elucidation and toxicity assessment

Microbial degradation of chloramphenicol (CAP) has become important for reducing the adverse impact of environmental pollution with antibiotics. Although several pathways for CAP degradation have been identified in various bacteria, multiple metabolic pathways and their respective intermediate metabolites within a single strain are rarely reported. Here, Raoultella ornithinolytica CT3 was first isolated from silkworm excrement using CAP as the sole carbon source, and 100 mg/L CAP was almost completely degraded within 48 h. The biodegradation type of CAP followed first-order kinetics. Twenty-two CAP biotransformation products were identified using high-performance liquid chromatography and ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry. The CAP biotransformation pathways were predicted mainly in the acetylation and auxiliary pathways of propionylation and butyrylation. The toxicity of CAP biotransformation products was evaluated using the ecological structure-activity relationship (ECOSAR) model and biological indicators. The results showed that the toxicity of the intermediate metabolites changed slightly, but the final metabolite was harmless to the environment. Genomic analysis predicted that genes encoding acetyltransferase, amido-linkage hydrolase, nitroreductase, haloacetate dehalogenase, and protocatechuate 3,4-dioxygenase were associated with CAP biodegradation. This study provides new insights into the microbial degradation pathway of CAP and constitutes an ecological safety assessment for CAP-contaminated environments.

Efficient photocatalytic degradation of chloramphenicol from contaminated water over rGO@MoS2 nanocomposites

Antibiotics-based effluents pose a severe threat to the natural ecosystem by acting as reservoirs for the growth of drug-resistant bacteria if untreated. Herein, a facile and scalable approach was developed to engineer photocatalysts associating reduced graphene oxide (rGO) and molybdenum disulfide (rGO@MoS2) that were used for the degradation of chloramphenicol (CAP) from contaminated water under UV-light. The hydrothermally produced rGO@MoS2 catalysts contain CO, COH, and COC functional groups that contribute to the binding of CAP onto their surface. The rGO surface modification with MoS2 layers offers a high surface area for light absorption. Results show that the rGO@MoS2 catalyst (1:1 w/w) exhibits the highest degradation efficiency (DE) of 86 % within 180 min of light exposure at neutral pH. Further, the kinetic modelling studies for CAP degradation by rGO@MoS2 1:1 showed high linearity with pseudo-first order kinetics (R2 ∼ 0.9). The isotherm modelling studies correspond to Langmuir isotherm (R2 ∼ 0.99), suggesting monolayer-type interaction of CAP with the photocatalyst surface during photodegradation. Furthermore, the mechanism of degradation elucidated using scavenging experiments showed the involvement of both holes (h+) and electrons (e−) that contribute to the degradation of CAP by generating reactive oxygen species (ROS) like OH● and O2●− radicals. The applicability of the rGO@MoS2 photocatalyst towards the degradation of CAP was tested in Ganga water, wherein a similar ∼86 % CAP removal was observed. Furthermore, the photocatalyst was found to be stable and could be reused five times. Overall, these findings demonstrate the usefulness of the rGO@MoS2 1:1 composite as an efficient photocatalyst that can be used for the degradation of harmful organic pollutants from water bodies to provide a safer and cleaner environment.

Electro-, photo-, and photoelectrochemical degradation of chloramphenicol on self-doping Ti nanotubes.

In this work, the photo-, electro-, and photo-electro-oxidation of chloramphenicol was investigated. The photo-experiments were carried out with different irradiation sources (an ultraviolet and a simulated solar source) using self-doped titanium nanotubes (SDTNT), a very promising and innovative material that deserves further investigations in the degradation of different pollutants. The photo-electrooxidation (j = 15mAcm-2) under simulated solar irradiation presented the best efficiency, with ca. 100% degradation and kinetic constant of k = 0.04427min-1. The FTIR analysis demonstrated a structural modification of the standard molecule occurred for all conditions used, suggesting a modification in functional groups responsible for the biological activity. Furthermore, the TOC analysis showed a significant mineralization of the pollutant (66% from the initial concentration). In addition, both photo-electrooxidation approaches have demonstrated a positive value of S, where the simulated solar irradiation reached the highest value S = 0.6960. The experimental results pointed out evidence that the methodology employed herein for chloramphenicol degradation is greatly interesting and the photo-electrooxidation under simulated solar irradiation is a promising approach for this purpose.

Heterogeneous degradation of chloramphenicol antibiotic by peroxymonosulfate activated by FeS and FeS2: Mechanism and effects of catalysts dosage and pH

Antibiotics in the environmental waters pose long-term threat to ecological safety because of their persistent and potential toxic nature. FeS and FeS2 were proved to be efficient catalysts for the activation of peroxymonosulfate (PMS) and the generation of sulfate radical generation for refractory pollutant degradation. However, their performance for antibiotic degradation has not yet been comparatively and comprehensively investigated. Herein, the FeS/PMS and FeS2/PMS systems were developed to explore chloramphenicol (CAP) degradation under equal conditions. The results show that CAP was efficiently degraded in both two systems, with a removal efficiency exceeding 90 % within 120 min using 6 mM PMS and 0.6 g/L catalysts.Acceleration in degradation rate was observed in the FeS2/PMS system when the catalyst dosage ranged from 0.1 g/L to 1.0 g/L (constant PMS concentration) with a reaction rate constant (kobs) of 2.1-fold higher than that in the FeS/PMS system. However, the kobs were comparable with the PMS concentration range (constant catalyst dosage) in the two systems, suggesting that the catalysts were the rate-limiting step in CAP degradation process. The initial pH strongly affected CAP degradation in the FeS/PMS system but had little effect on that in the FeS2/PMS system. Surface Fe2+ played a dominant role in PMS activation, and S22−/S2− facilitated Fe2+ regeneration. Further, both FeS and FeS2 had stable activity for PMS activation during long-term use. This study proves the effectiveness of FeS and FeS2 for PMS activation for antibiotic degradation and differentiates their catalytic qualities, which will provide alternative heterogeneous catalysts for practical application.

Modified sono-Fenton process for oxidative degradation of chloramphenicol.

Oxidative degradation of chloramphenicol (CAP) using a hybrid approach (US/HA+/n-Fe2O3/SPC) involving sodium percarbonate (SPC; "solid H2O2" carrier), Fe2O3 nanoparticles (n-Fe2O3; H2O2 decomposition catalyst), hydroxylamine in its protonated form (HA+; Fe (III) to Fe (II) reducer), and ultrasonic cavitation (to increase the generation of hydroxyl radicals) has been studied for the first time. The average size of n-Fe2O3 synthesized by the sonochemical method, as calculated according to the Debye-Scherrer equation, was ~ 18nm. The maximum degradation degree of CAP (83.1%) and first-order oxidative degradation rate constant of CAP as 1.253 × 10-3s-1 were achieved using the modified sono-Fenton process under the optimized conditions as the initial concentration of CAP - 50mg/L, the molar ratio of CAP:HA+:n-Fe2O3:SPC of 1:100:100:100, pH as 3, the temperature as 318K, the specific ultrasonic power as 53.3 W/L, and the treatment duration of 7200s. In general, the efficiency and intensity of CAP degradation increased with a decrease in the pH value, an increase in the molar ratio of CAP:HA+:n-Fe2O3:SPC, a decrease in the initial concentration of CAP, an increase in temperature, and showed a minor change with the specific power of US. The synergistic coefficient for the combination of the US and the heterogeneous Fenton process was 17.9. The active participation of hydroxyl radicals in the oxidative degradation of CAP using the modified sono-Fenton process was confirmed by scavenging experiments performedusing tert-butyl alcohol. The proposed process can be a promising direction in the remediation of pharmaceutical effluents with significant potential for commercial exploitation.

Synergistic nanomaterial system for luminescence sensing of MnO4- anion and enhanced photocatalytic removal of antibiotic chloramphenicol (CAP) in aqueous environments using Dy3+/Tb3+ co-doped NaYF4 and graphene oxide hybrid

The presence of industrial pollutants in water bodies, particularly metal anions and organic pollutants, has put human health and the environment at risk worldwide, triggering the research and development of multifunctional nanoparticles that not only have excellent luminescence detection ability but also possess simultaneous photo-degradation activity against harmful pollutants. Herein, we have synthesized Dy3+/Tb3+ co-doped NaYF4 (Tb-NP) and (Tb-GO) NaYF4:Dy3+/Tb3+@GO(GO=Graphene oxide) nano hybrids via hydrothermal approach and tested their functional activity for the fluorescence selective detection of MnO4- anions and photocatalytic degradation of drug Chloramphenicol (CAP) in aqueous medium. The physicochemical characterization of prepared nanosamples was examined utilizing variety of analytical methods. The luminescent property of NaYF4:Dy3+/Tb3+(7 %) revealed that it is exceptionally sensitive and selective towards the detection ofMnO4- anion in aqueous medium. It was observed that, when varied amount of MnO4- anion was added to a suspension solution containing the synthesized NaYF4:Dy3+/Tb3+(7 %) chemosensor, the photoluminescence emission band at 545 nm was significantly quenched. Moreover, NaYF4:Dy3+/Tb3+(Tb-NP) exhibited the limit of detection (LOD)value of 0.65 ppm along with high Stern-Volmer (Ksv) quenching constant value of 4.75 ×105 M−1 for MnO4- anion, indicating great selectivity and sensitivity of the designed nanosensors towards MnO4- anion. Further, the Graphene oxide (GO) conjoined NaYF4:Dy3+/Tb3+(7 %) nanohybrid showed accelerating photocatalytic activity toward the degradation of CAP in aqueous medium under UV-irradiation. The obtained results of UV-Vis spectroscopy clearly indicate that NaYF4:Dy3+/Tb3+@GO (Tb/GO) nanohybrid can act as a superior nanocatalyst than that of NaYF4:Dy3+/Tb3+(Tb-NP) nanophosphors. The photocatalytic efficiency of NaYF4:Dy3+/Tb3+@GO (Tb/GO) nanohybrid toward degradation of CAP is around 95.6 % within 50 minutes under UV light and it maintains remarkable stability even after five repeated catalytic cycles. In conclusion, this study presents a feasible method for immediate detection of MnO4- anion and improved photo-catalytic degradation of CAP in an aqueous medium employing NaYF4:Dy3+/Tb3+(Tb-NP) and NaYF4:Dy3+/Tb3+@GO (Tb/GO) as dual functional nanomaterials.

N, O Co‐Doping Enhanced Adsorption of Chloramphenicol for Highly Efficient and Robust Electrocatalytic Hydrodechlorination

Comprehensive SummaryElectrocatalysis technology can effectively promote the hydrodechlorination of chloramphenicol (CAP) to reduce the bio‐toxicity. However, there are still some challenges such as low degradation rate and poor stability. Here, we prepared porous N, O co‐doped carbon supported Pd nanoparticles composites (Pd NPs/NO‐C) for electrocatalytic degradation of CAP. The doping of N and O not only effectively enhanced the interaction between substrate and CAP, promoting the mass transfer process, but also enhanced the anchoring effect on Pd nanoparticles, avoiding the occurrence of aggregation. The prepared composites achieved removal efficiency of CAP over 99% within 1 h, and the rate constant was as high as 6.72 h–1, outperforming previous reported electrocatalysts. Additionally, Pd NPs/NO‐C composites showed a wide range of pH tolerance, excellent ion interference resistance and long‐term stability. Our work unravels the importance of mass transfer processes in solution to electrocatalytic hydrodechlorination and provides new research ideas for catalysts design.

Hunting of “two birds with one arrow” strategical design of Nb doped WO3 decorated on the BN nanosheet and their enhanced photocatalytic degradation of Rose Bengal dye and Chloramphenicol drug

In the present work, “Killing two birds (RB and CAP) with one arrow (Nb/WO3/BN)” plan of action was performed for the photocatalytic degradation of organic dye of Rose Bengal (RB) and organic drug of Chloramphenicol (CAP) was degraded under visible light irradiation with the active catalyst of Nb/WO3/10 % BN composite for first time. The as-prepared Nb/WO3 was functionalized with thin-sheet structure of BN nanocomposite was synthesized via acid precipitation method followed by ultra-sonication method. The effective formation of Nb/WO3/BN were characterized by using XRD, UV-DRS, XPS, SEM-EDS, TEM, Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). The XRD, UV-DRS results clearly revealed that formation of ternary phases in the composites. Formation of ternary composite also confirmed by the XPS analysis. The morphology of WO3, Nb/WO3 and BN were examined by the SEM analysis. Furthermore, the inner morphology of cubic structure of WO3 nanoparticles and Nb/WO3 were decorated on the surface of the BN nanosheet were approved by TEM analysis. Interestingly, photocatalytic degradation of RB revealed by 94.31 % within 60 min as well as CAP degraded 95.13 % within 60 min by Nb/WO3/10 % BN ternary composite under visible light irradiation. Meanwhile, the different prepared photocatalyst, Nb/WO3/10 % BN was found to be the most efficient photocatalyst for degradation of RB and CAP. This results ascribed to the 30 mg of the photocatalyst and 10 mg/L concentration were optimum loading for the degradation of RB and CAP. Scavenger studies were also confirmed in order to understand the mechanism of photodegradation process. It was noted that electrons and holes pair are generated by irradiation of light, followed by (.OH) radical plays a crucial role for the photodegradation mechanism. The active photocatalyst Nb/WO3/10 % BN shows a good stability at room temperature and it can be recycled and reused up to five successful cycles without the major loss in their performances. Therefore, these work revealed that, the best sequence of Nb/WO3/10 % BN nanocomposite is new plan of action for photodegradation of RB and CAP.

Enhanced activation of peroxymonosulfate on layered molybdenum disulfide loaded with Co–La bimetallic oxide for efficient degradation of chloramphenicol

Enhanced activation of peroxymonosulfate on layered molybdenum disulfide loaded with Co–La bimetallic oxide for efficient degradation of chloramphenicol

Synergistic effect on simultaneous treatment of Cr(VI) and chloramphenicol using a non-thermal plasma technology

Toxic organic and heavy metal contaminants commonly exist in industrial waste stream(s) and treatment is of great challenge. In this study, a dielectric barrier discharge (DBD) non-thermal plasma technology was employed for the simultaneous treatment of two important contaminants, chloramphenicol (CAP) and Cr(VI) in an aqueous solution through redox transformations. More than 70% of CAP and 20% of TOC were degraded in 60 min, while Cr(VI) was completely removed in 10 min. The hydroxyl radicals were the main active species for the degradation. Meanwhile, the consumption of hydroxyl radicals was beneficial to the reduction of Cr(VI). The synergistic effect was investigated between CAP degradation and Cr(VI) reduction. The reduction of Cr(VI) would be enhanced in the presence of CAP with a low concentration and could be inhibited under a high concentration, because part of hydroxyl radicals could be consumed by the low-concentration CAP and the obtained intermediates with a higher kinetic rate. However, CAP with a high concentration could react with such reductive species as eaq− and •H, which could compete with Cr(VI) and inhibit the reduction. In addition, the presence of Cr(VI) enhanced the degradation and mineralization of CAP; the study of obtained intermediates indicated that the presence of Cr(VI) changed the degradation path of CAP as Cr(VI) would react with reductive species, enhance the generation of hydroxyl radicals, and cause more hydroxylation reactions. Moreover, the mechanism for the simultaneous redox transformations of CAP and Cr(VI) was illustrated. This study indicates that the DBD non-thermal plasma technology can be one of better solutions for simultaneous elimination of heavy metal and organic contaminants in aquatic environments.

Antibiotic Chloramphenicol degradation using submerged thermal plasma synergized with LaMnO3 catalyst

The present study focused on the degradation of antibiotic Chloramphenicol (CAP), an emerging contaminant, using submerged thermal plasma (STP) technology. Almost 99 % degradation and 82 % mineralization were achieved within 20 min of treatment by Ar/CO2 plasma, generated at 6.2 kW discharge power using a customized thermal plasma torch inside the aqueous solution. Kinetic analysis revealed first-order reaction for CAP degradation with a rate constant of 0.257 min−1. Long-lived species, such as H2O2, O3, NO2–, NO3–, and Cl- formed during plasma treatment were quantified. LaMnO3 perovskite (LMO) nanopowder prepared through a novel thermal plasma route, was introduced as catalyst into the treatment system which enhanced the degradation and mineralization efficiency by 34 % and 17 %, respectively, showing a strong synergetic effect between STP and catalyst. The energy yield was elevated from 102 mg/kWh to 144 mg/kWh with the addition of catalyst into the STP treatment system. Liquid chromatography-mass spectroscopy was used to identify the various degradation intermediates produced during thermal plasma treatment and correspondingly possible degradation pathways were proposed. The antibacterial activity assessment results revealed a significant reduction in the antimicrobial activity of all treated solutions against Gram-positive Bacillus cereus and Gram-negative Pseudomonas aeruginosa bacteria. Additionally, seed germination and growth assessment revealed a reduction in phytotoxicity of the treated solutions. STP, combined with the LMO, proved highly effective in treating pharmaceutical contamination in aqueous medium.

Effective photocatalytic degradation of antibiotic chloramphenicol and anionic direct violet 51 dye using g-C3N4 embedded NiO nanocomposite

Effective photocatalytic degradation of antibiotic chloramphenicol and anionic direct violet 51 dye using g-C3N4 embedded NiO nanocomposite

Expression of Concern: Effective degradation of chloramphenicol in wastewater by activated peroxymonosulfate with Fe-rich porous biochar derived from petrochemical sludge

Expression of Concern: Effective degradation of chloramphenicol in wastewater by activated peroxymonosulfate with Fe-rich porous biochar derived from petrochemical sludge

Unexpectedly enhanced degradation of acetaminophen by sulfoxides probe in Fe(II)-activated persulfate oxidation: The mechanism and the selectivity

Sulfoxides are widely recognized as probes for identifying and evaluating the generation and contribution of high-valent metals in advanced oxidation processes. However, this paper was surprising to find that the presence of sulfoxides selectively enhanced the degradation of specific pollutants in the Fe(II)/PS system. Represented by methyl phenyl sulfoxide (PMSO), scavenging experiments for active species showed that the presence of PMSO transformed the mechanism from radical dominated (55.60 %) to nonradical dominated (60.91 %), greatly improving the anti-interference ability of the system. Determining the concentration of Fe(Ⅱ) and total iron (Fetot) in solution revealed that the presence of PMSO improved the utilization efficiency of Fe(II) and PS by enhancing the redox reaction between Fe(II) and PS, and resulted in the generation of Fe(IV) more favorably than the generation of SO4·− and ·OH. Additionally, comparing the proven high-valent iron dominated Fe(II)/PI system with the free radical dominated Fe(II)/PS system of this paper, it was revealed that the selectively enhanced oxidation of PMSO specifically targets the free radical dominated system. Experiments have shown that the degradation of acetaminophen, ibuprofen, phenol, and p-chlorophenol was enhanced by PMSO, while the degradation of norfloxacin, primidone, chloramphenicol, sulfamethoxazole, p-nitrophenol, benzoic acid, and nitrobenzene was inhibited. Based on density functional theory (DFT) calculations, PMSO has a selectively enhanced degradation effect for organic pollutants with ionization potential (IP) below 8.66 eV, and vice versa, it has an inhibitory effect. The present study provides new insights into the contribution of sulfoxide to the assessment of high-valent metals and sheds new light on the mechanism of active species.

Revealing the biological significance of multiple metabolic pathways of chloramphenicol by Sphingobium sp. WTD-1

Chloramphenicol (CAP) is an antibiotic that commonly pollutes the environment, and microorganisms primarily drive its degradation and transformation. Although several pathways for CAP degradation have been documented in different bacteria, multiple metabolic pathways in the same strain and their potential biological significance have not been revealed. In this study, Sphingobium WTD-1, which was isolated from activated sludge, can completely degrade 100 mg/L CAP within 60 h as the sole energy source. UPLC-HRMS and HPLC analyses showed that three different pathways, including acetylation, hydroxyl oxidation, and oxidation (C1-C2 bond cleavage), are responsible for the metabolism of CAP. Importantly, acetylation and C3 hydroxyl oxidation reduced the cytotoxicity of the substrate to strain WTD-1, and the C1-C2 bond fracture of CAP generated the metabolite p-nitrobenzoic acid (PNBA) to provide energy for its growth. This indicated that the synergistic action of three metabolic pathways caused WTD-1 to be adaptable and able to degrade high concentrations of CAP in the environment. This study deepens our understanding of the microbial degradation pathway of CAP and highlights the biological significance of the synergistic metabolism of antibiotic pollutants by multiple pathways in the same strain.

Ce/Fe bimetallic MOF derivatives in situ modified bulk carbon aerogel composite cathode for efficient heterogeneous electro-fenton degradation of chloramphenicol

In this study, we utilized a Ce-modified iron-based metal-organic framework derivative to in situ modify bulk CA (Ce/Fe@C-CA) as a bifunctional composite cathode to degrade chloramphenicol (CAP) in the heterogeneous electro-Fenton (EF) process. The composite cathode exhibited satisfactory CAP degradation efficiency, wide pH adaptability (2–9) and low metal leaching. Under the appropriate conditions (pH = 5, current density = 6 mA/cm2), 94.89% of CAP degradation efficiency was obtained within 60 min. The introduction of Ce increased the oxygen vacancy content, enhanced the cathodic electrochemical activity, promoted the production of a variety of reactive oxygen species and participates in the degradation of CAP, of which ·OH and 1O2 were dominant. Meanwhile, the electron transfer and synergistic catalysis between Ce and Fe promoted the regeneration of the metal active site, which was beneficial to improve the reuse stability of the Ce/Fe@C-CA cathode. The degradation pathway of CAP was obtained by DFT calculations and UPLC-MS/MS detection. This study not only proposed a novel bifunctional electro-Fenton cathode, but also provided a effective strategy for the treatment of actual pharmaceutical wastewater.

Laser flash photolysis and quantum chemical studies of UV degradation of pharmaceutical drug chloramphenicol: Short-lived intermediates, quantum yields and mechanism of photolysis

Using methods of time-resolved and stationary photolysis, HPLC-MS and quantum-chemical calculations by the DFT method, the mechanism of direct UV photolysis of the antibiotic chloramphenicol (CAP) was established. For the first time, short-lived intermediates formed during photolysis were detected. The primary photoprocess is the cleavage of the β-C-C bond relative to the aromatic system with the formation of 4-nitrobenzylalcohol radical and residual aliphatic radical. The first radical in deoxygenated solutions predominantly transforms into para-nitrobenzaldehyde and its secondary photolysis products. In the presence of oxygen, the aromatic radical and para-nitrobenzaldehyde are transformed into para-nitrosobenzoic and para-nitrobenzoic acids as a result of reaction with reactive oxygen species (ROS). Formation of ROS is provoked by reactions of aliphatic radical with dissolved oxygen, so this radical is very important for CAP degradation. The quantum yield of direct photolysis of CAP is ∼3% and does not depend on the presence of dissolved oxygen and on the change of the excitation wavelength in the range of 254–308 nm. Obtained data are important for further understanding of the transformation pathways of CAP and similar PPCP in natural and wastewaters under the action of sunlight and artificial UV radiation.

Cathodic membrane with confined interlayer spacing for efficient electrocatalytic dehalogenation of antibiotics

Conventional catalytic membranes often exhibit inadequate catalytic efficiency due to limited retention time for pollutants during filtration. In this study, a single-atom catalyst (Ni-NG) was prepared by dispersing single nickel atoms onto nitrogen-doped graphene oxide sheets. Subsequently, under controlled conditions, the assembly of Ni-NG with reduced graphene oxide (rGO) sheets led to the fabrication of efficient electrocatalytic cathodic membranes (ECMs). The ECMs were designed to concentrate and dehalogenate antibiotics simultaneously by utilizing the confined single nickel atoms within the multilayered ECMs through electrocatalytic reduction. Remarkably, complete degradation of chloramphenicol (CAP, 20 mg L−1) in the solution was achieved within a remarkably short time of 3.0 ms by ECM8 which had an area of 7.1 cm2 and comprised Ni-NG (16.9 μg) and rGO (16.9 μg), with an interlayer spacing of 0.37 nm, during filtration (40 L m−2 h−1). The reaction rate constant (k) for CAP degradation by ECM8 was approximately 3 × 108 min−1, surpassing the highest value in the literature. Furthermore, the ECM demonstrated both high energy efficiency and stability, highlighting the great potential for practical applications. The electrocatalytic cathodic membrane, designed to primarily concentrate pollutants in confined interlayer spaces through the sieving effect, shed lights on the highly efficient dehalogenation of organic compounds in pharmaceutical salt-laden wastewater.

DBDP collaboration Cu@PAF-45-COOH experimental study on catalytic degradation of chloramphenicol in water

DBDP collaboration Cu@PAF-45-COOH experimental study on catalytic degradation of chloramphenicol in water