Degradation Of Doxycycline Research Articles

Nitrogen-doped carbonized polyaniline (N-CPANI) for peroxydisulfate (PDS) activation towards efficient degradation of doxycycline (DOX) via the non-radical pathway dominated by electron transfer

In this study, nitrogen-doped carbonized polyaniline (N-CPANI-T, T is the carbonized temperature) was firstly synthesized to activate peroxydisulfate (PDS) towards the sustainable degradation of doxycycline (DOX). Compared to other carbon-based catalysts reported in the previous studies, N-CPANI-900 had better DOX decomposition rate (91.66 %) and higher TOC elimination efficiency (83.77 %) within 120 min with the initial DOX concentration as high as 20 mg/L, which could be attributed to the accelerated electron transfer and the large adsorption capacity of N-CPANI-900. The active sites for PDS activation driven by N-CPANI-900 mainly include graphitic N, ketonic group (CO) and defect sites in the carbon matrix. The results of both quenching experiments and electron paramagnetic resonance (EPR) test illustrated that non-radical pathway was dominated in the N-CPANI-900/PDS/DOX system. Moreover, metastable N-CPANI-900/PDS complexes mediated electron transfer made a remarkable contribution to DOX degradation compared with singlet oxygen. The effects of pH, inorganic anions, NOM and different water matrices on DOX degradation were almost negligible in the N-CPANI-900/PDS system. This research provides a new strategy into the preparation of metal-free PDS activators towards efficient removal of emerging contaminants in real wastewater.

FeNi-layered double hydroxide (LDH)@biochar composite for , activation of peroxymonosulfate (PMS) towards enhanced degradation of doxycycline (DOX): Characterizations of the catalysts, catalytic performances,degradation pathways and mechanisms

In this study, FeNi-layered double hydroxides (LDH)@biochar composite material was prepared by hydrothermal method and used for peroxymonosulfate (PMS) activation towards the efficient degradation of doxycycline (DOX). The as-prepared materials were thoroughly characterized by SEM, BET, XRD, XPS and FTIR. The DOX removal in different systems (LDH@biochar + PMS, LDH + PMS and biochar + PMS) were compared accordingly. And the results demonstrated that the FeNi-LDH@biochar displayed a much higher DOX removal efficiency (88.1%) than FeNi-LDH (77.1%) and biochar alone (75.4%). In addition, the effects of catalyst dosage, PMS concentration, initial pH value on the DOX removal were evaluated. 88.1% of parent contaminant could be decomposed in the presences of 0.50 g/L catalyst, 0.75 g/L PMS at initial pH 4.5 (without pH adjustment), with TOC removal efficiency of 62.9%. The introduction of biochar to LDH catalyst could lead to the involvement of non-radical-based oxidation in DOX degradation. The DOX removal is less affected by the co-existing ions and organics of the actual aquatic environment. Three possible DOX decomposition pathways were inferred according to the identification of transformation intermediates by HPLC-MS. The ECOSAR analysis indicated that the toxic abatement was demonstrated for most of the transformation products during DOX degradation. In the reusability assay, the DOX removal efficiency dropped from 88.1% to 77.2% after five cycles, and recovered to 86.6% via regeneration. The results of both quenching experiment and EPR analysis showed that the SO4•-, •OH, •O2− and 1O2 all did contribute to the DOX decontamination. DFT calculation results showed that LDH@biochar composite exhibited stronger adsorption capacity for PMS and the thermodynamic feasibility of reaction was further demonstrated by the energy barrier of reaction pathways.

Green synthesis of two-electron centre based ZnO/NiCo2S4 QDs-OVs using Punica granatum fruit peel extract for an exceptional visible light photocatalytic degradation of doxycycline and ciprofloxacin.

Biosynthesis of nanomaterials using plant extract makes them attractive in the field of photocatalysis as they are environmental friendly. The current study focused on the biosynthesis of ZnO/NiCo2S4 QDs (NCs) using Punica granatum fruit peel extract as the reducing agent. The nanomaterials were characterized with XRD, FTIR, Raman, SEM, TEM, UV-vis DRS, BET, PL, EIS, and ESR analysis and were used for photocatalytic degradation of doxycycline (DOX) and ciprofloxacin (CIP). The bandgap of ZnO is 3.2eV, and the decoration of NiCo2S4 QDs aids in narrowing the bandgap (2.8eV), making the NCs visible light active. The fabricated NCs achieved 99 and 89% degradation of DOX and CIP respectively. The photocatalytic efficiency of ZnO/NiCo2S4 QDs was much higher compared to individual ZnO and NiCo2S4 QDs. The half-life period of DOX and CIP were evaluated to be 58 and 152min respectively. The percentage of TOC removal in the photodegraded product of DOX and CIP was estimated to be 99 and 89% respectively, indicating the mineralization of the compounds. The enhanced photocatalytic efficiency of the NCs was attributed to the narrowed visible light active bandgap, synergistic charge transfer across the interface, and lower charge recombination. The intermediates formed during the photocatalytic degradation of DOX and CIP were analyzed using GC-MS/MS analysis, and the photodegradation pathway was elucidated. Also, the toxicity of the intermediates was computationally analyzed using ECOSAR software. The fabricated ZnO/NiCo2S4 QDs have excellent stability and reusability, confirmed by XRD and XPS analysis. The reusable efficiency of the NCs for the photocatalytic degradation of DOX and CIP were 98.93, and 99.4% respectively. Thus, the biologically fabricated NCs are shown to be an excellent photocatalyst and have wide applications in environmental remediation.

Synthesis of Controlled-Release Calcium Peroxide Nanoparticles Coated with Dextran for Removal of Doxycycline from Aqueous System.

Nanoscale calcium peroxide (nCP) has turned out to be one of the effective and environmentally friendly approaches for wastewater remediation purposes. The rapid hydrolysis of nCPs and burst oxygen release caused by the high surface-to-volume ratio of nCPs could surpass the appropriate demand for oxygenation and pollutant degradation in the aqueous system. Thus, coated oxidants (COs) have been prepared using polymeric materials to ensure long-term efficacy and slow-release capability. Therefore, the nCPs were first prepared using dextran as a stabilizer to prevent irreversible agglomeration by the chemical precipitation method and had an average mean size of 2.33 ± 0.81 nm. The synthesized nCPs were then coated with dextran to produce dextran-coated nCPs. Their characteristics and effectiveness in doxycycline (DOX) degradation were assessed. The characterization of nCPs and dextran-coated nCPs was performed using X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), Brunauer, Emmett and Teller analysis (BET), dynamic light scattering (DLS) and thermogravimetric analysis (TGA) techniques. This work suggests that dextran-coated nCPs are beneficial in wastewater treatment practice in terms of the long-term efficacy of DOX degradation potential.

Unsaturated Nd-Bi dual-metal sites enable efficient NIR light-driven O2 activation for water purification

Metal semiconductor catalysts with oxygen vacancies can make full use of near infrared light to active O2 for degradation of emerging pollutants. However, the surface oxygen vacancies can also become the combination center of electron-hole pairs, leading O2 cannot accept more electrons for activation, often becoming the bottleneck. In this study, by doping half-metal BiO2−x with Nd to form unsaturated Nd-Bi dual-metal sites as oxygen chemisorption and electron transfer sites, this bottleneck can be well solved. Systematic characterization results imply that Nd-Bi dual-metal sites can raise the center of the defect band to the Fermi level, which preserves the energy of photoexcited electrons. Thus, more electrons are driven to adsorbates for O2•- generation. Under liquid phase determination conditions, the modified sample achieves the reaction-rate constant for doxycycline degradation of 134.4 × 10−4 min−1, which is about 24.2 times higher than that of pristine BiO2−x under NIR irradiation.

Mechanochemical synthesis of La-Sr-Co perovskite composites for catalytic degradation of doxycycline in the dark: Role of oxygen vacancies

Direct heterogeneous catalysis is conducted to decontaminate antibiotic polluted water for the first time. Perovskite-structured composites LaxSr(1-x)CoO3-δ (LSC) are synthesized by a green mechanical milling method (as it involves no organic solvent, generates no wastewater, and is viable for industrial-scale use) and applied for the efficient catalytic degradation of doxycycline (DC) via singlet oxygen without the addition of chemical reagents or illumination. The oxygen vacancy produced during ball milling stores numerous electrons. These electrons and singlet oxygen exert a synergistic effect on the catalytic reaction, thereby improving the catalytic degradation of DC. LSC can effectively catalyze the degradation of DC in the dark. The total organic carbon removal efficiency reaches 89.64%, indicating that most DC is eventually mineralized to CO2 and H2O. The catalytic degradation of DC follows two principal degradation pathways involving 13 intermediates. Toxicity prediction indicates that the toxicity of the products initially increases and then decreases with the degradation process and that the final products are not toxic. This study not only allows a facile synthesis route for catalyst preparation but also promotes the development of a green method for wastewater treatment.

Electrochemical degradation of doxycycline in a three-dimensional vermiculite/peroxymonosulfate electrode system: Mechanism, kinetics, and degradation pathway

In this study, vermiculite (VER) powder was used as a particle electrode in a three-dimensional (3D) Ti-IrO2/Ta2O5 electrode system for the electrochemical degradation of doxycycline (DOX) combined with peroxymonosulfate (PMS) activation. The effects of operational parameters (such as VER dosage, PMS concentration, initial pH, and current density) on DOX degradation were studied and the optimal parameters were discussed. Electrochemical degradation and electrochemical analysis showed that the addition of VER particles could improve the electrochemical conversion efficiency of the 3D electrochemical system by increasing the oxygen evolution potential and inhibiting the occurrence of oxygen evolution side reactions. Quenching experiments showed that sulfate free radicals are the leading reactive oxygen species in the system. A possible pathway for DOX degradation by the reaction system was proposed based on intermediates detected using liquid chromatography–electrospray ionization–quadrupole–time of flight (LC–ESI–Q–TOF). The toxicity of all the intermediates was predicted using the ECOSAR program. Our study showed that the 3D VER/PMS electrode system was reliable for repairing surface water or groundwater polluted by antibiotics.

Preparation of a ruthenium-modified composite electrode and evaluation of the degradation process and degradation mechanism of doxycycline at this electrode

Electrocatalytic method is widely used in the treatment of antibiotic wastewater. In this study, an efficient and stable ruthenium/agarose/copper foam (Ru/AG/CF) composite electrode was prepared by making full use of the properties of agarose and Ru. This electrode not only has a good catalytic effect, but also has a high stability. The morphology, crystal structure, and element valence of the composite electrodes were observed and analyzed by SEM, XRD, and XPS, respectively. The electrodes can achieve a degradation efficiency of 79.12% for a 10 mg/L solution of doxycycline in 120 min. The kinetics of the doxycycline degraded by Ru/AG/CF electrode was found to be pseudo-first-order kinetics and was fitted to the Langmuir–Hinshelwood model. Toxicity tests on doxycycline degradation solution using E. coli showed that the toxicity of doxycycline degradation solution was basically negligible and had a certain degree of safety. The products of doxycycline were analyzed by hydroxyl radical detection experiments using LC-MS. The degradation pathway of doxycycline was proposed. The removal efficiency of doxycycline was basically unchanged after 10 consecutive applications. The good degradation efficiency, good reusability and good safety showed that the electrode is a promising material for practical applications in water treatment.

Robust Adsorption and Persulfate-Based Degradation of Doxycycline by Oxygen Vacancy-Rich Copper-Iron Oxides Prepared through a Mechanochemical Route

Robust Adsorption and Persulfate-Based Degradation of Doxycycline by Oxygen Vacancy-Rich Copper-Iron Oxides Prepared through a Mechanochemical Route

α-Bi2(MoO4)3 nanorods decorated with two-dimensional g-C3N4 nanosheets for efficient degradation of doxycycline under visible light illumination

Water pollution caused by pharmaceutical and personal care products (PPCPs) has been significant stress on the water management system. The development of effective and recyclable material for PPCPs removal has become essential. In the present work, a highly efficient g-C3N4/α-Bi2(MoO4)3 nanocomposites was prepared by a simple wet impregnation method and investigated as a catalyst for the photocatalytic degradation of doxycycline under visible light irradiation. The as-prepared catalysts with various mass ratios were systematically characterized with XRD, FT-IR, UV−vis, FE-SEM, EDX, FE-TEM, and XPS. The equal weight ratio (50:50) of g-C3N4/α-Bi2(MoO4)3 nanocomposite exhibits excellent visible light absorption and outstanding doxycycline photodegradation due to the improved separation efficiency of photo-generated charge carriers. After four consecutive cycles, the equal weight ratio (50:50) of g-C3N4/α-Bi2(MoO4)3 nanocomposite shows superior photostability. The scavenger study was carried out to investigate the role of active species in photodegradation activity. More superoxide radicals present on the surface of g-C3N4/α-Bi2(MoO4)3 nanocomposites can significantly enhance the photocatalytic performance. Therefore, a simple wet impregnation method was used to produce a low-cost g-C3N4/α-Bi2(MoO4)3 photocatalyst with the influential effects of removing pharmaceutical contaminants in water bodies.

Application of pulse-modulated radio-frequency atmospheric pressure glow discharge for degradation of doxycycline from a flowing liquid solution.

Doxycycline (DOX), an antibiotic commonly used in medicine and veterinary, is frequently detected in natural waterways. Exposition of bacteria to DOX residuals poses a selective pressure leading to a common occurrence of DOX-resistance genetic determinants among microorganisms, including virulent human pathogens. In view of diminishment of the available therapeutic options, we developed a continuous-flow reaction-discharge system generating pulse-modulated radio-frequency atmospheric pressure glow discharge (pm-rf-APGD) intended for DOX removal from liquid solutions. A Design of Experiment and a Response Surface Methodology were implemented in the optimisation procedure. The removal efficiency of DOX equalling 79 ± 4.5% and the resultant degradation products were identified by High-Performance Liquid Chromatography–Diode Array Detection, Liquid Chromatography Quadruple Time of Flight Mass Spectrometry, Ultraperformance Liquid Chromatography–Tandem Mass Spectrometry, total organic carbon, total nitrogen, Attenuated Total Reflectance Furrier Transform–Infrared, and UV/Vis-based methods. The pm-rf-APGD-treated DOX solution due to the generated Reactive Oxygen and Nitrogen Species either lost its antimicrobial properties towards Escherichia coli ATCC25922 or significantly decreased biocidal activities by 37% and 29% in relation to Staphylococcus haemolyticus ATCC29970 and Staphylococcus aureus ATCC25904, respectively. Future implementation of this efficient and eco-friendly antibiotic-degradation technology into wastewater purification systems is predicted.

Degradation of doxycycline antibiotics using lanthanum copper oxide microspheres under simulated sunlight.

In this study, lanthanum copper oxide was synthesized under hydrothermal techniques and characterized for doxycycline degradation. The catalyst exhibited enhanced photocatalytic doxycycline degradation under visible light owing to its compatible bandgap energy (1.7eV). The XRD data revealed high crystallinity of the material with no noticeable impurities. Three-dimensional microspheres of varying sizes (average diameter of 2.52μm) were observed from SEM. EDX confirms the successful synthesis of La2CuO4. The effect of DC concentration, catalyst dosage, and initial pH on the degradation rate of DC was studied methodically. Interestingly, about 85% of doxycycline (10mg/L) was degraded within 120min of light-emitting diode irradiation at pH 10. Oxygen vacancies and surface defects were determined through photoluminescence spectra. The recyclability experiments suggested that the catalyst is capable of degrading DC for three consecutive runs. Radical trapping trials suggested that holes (h+), superoxide radicals (●O2-), and hydroxyl radicals (●OH) are involved in the photodegradation of DC. Herein, the novel approach of La2CuO4 synthesis and the efficient visible-light harvesting capability of as-prepared catalyst reveal the potentiality for DC degradation thereby opening a new horizon of research employing La2CuO4 used for various environmental applications.

Corn husk multilayered graphene/ZnO nanocomposite materials with enhanced photocatalytic activity for organic dyes and doxycycline degradation

This study focuses on utilization of biomass waste for fabrication of multilayered graphene (MLG) via cellulose extraction. MLG nanosheets were synthesized from corn husk via alkali-acid treatments, pyrolysis, and activation. Initially, cellulose was extracted followed by carbonization and activation of the carbon material. Multilayered graphene/zinc oxide (MLG/ZnO) nanocomposite was synthesized through ex-situ casting of ZnO and MLG nanopowders. The photocatalytic degradation of congo red (CR) and rhodamine B (RhB) by MLG/ZnO photocatalyst under sunlight irradiation exhibited maximum degradations of 100 and 86%, respectively, while pristine ZnO gave degradations of 85 and 71% for RhB and CR, respectively. The obtained results validated high photocatalytic activity for the optimized MLG/ZnO nanocomposite in RhB and CR degradation under natural sunlight irradiation. The nanocomposite further demonstrates 95% degradation for doxycycline (DOX) under UV light. This work provides an insight into better ways of recycling biomass waste to fabricate valuable materials to solve environmental problems.

Degradation of Doxycycline, Enrofloxacin, and Sulfamethoxypyridazine under Simulated Sunlight at Different pH Values and Chemical Environments

In this work, the dissipation of the antibiotics doxycycline (DC) (from the group of tetracyclines), enrofloxacin (ENR) (a fluoroquinolone), and sulfamethoxypyridazine (SMP) (a sulfonamide) is investigated both under simulated sunlight and in the dark, at three different pH (4.0, 5.5, and 7.2), and in the presence of different salts and humic acids. The results indicate that all three antibiotics are very sensitive to photodegradation, and this sensitivity increased with rising pH values, from 4.0 to 7.2. The rise in pH also caused an increase in the degradation kinetic constants and a decrease in the half-lives of antibiotics. In general, the half-lives ranged from a few minutes to 6 h, depending on the pH conditions and the specific antibiotic, and followed the sequence DC > SMP > ENR, although at pH 5.5 the sequence changed to SMP > DC > ENR. After 24 h of simulated sunlight, mineralization was always lower than 10%, although the antibiotic was not quantifiable after the same time of exposure to light (24 h), which indicates that intermediate compounds were generated. The effect of the presence of salts on the dissipation of the three antibiotics was negligible for NaCl and NaNO3, while NaHCO3 did favor the dissipation of DC and ENR. The presence of humic acids showed no effect on the dissipation of SMP, and it only slightly increased the dissipation of DC and ENR. These results may be useful in the assessment of the persistence/degradation of the antibiotics studied when they reach different environmental compartments and may suffer exposure to light under different physicochemical conditions.

Doxycycline detection and degradation in aqueous media via simultaneous synthesis of Fe-N@carbon dots and Fe3O4-carbon dot hybrid nanoparticles: a one arrow two hawk approach.

The overuse of antibiotics in recent years presents a huge challenge to society for their removal from the environment. The prolonged presence of antibiotics as environmental pollutants results in the emergence of drug-resistant bacteria faster than new antibiotics to treat diseases they cause. Therefore, a rapid, sensitive, and cost-effective method is urgently required to detect and degrade antibiotics. Given this, a novel strategy has been devised for synthesizing Fe-doped carbon dots (Fe-N@CDs) and iron oxide-carbon dot hybrid nanoparticles (Fe3O4-CDs) in a single step for doxycycline detection and its degradation. For the very first time, the formation of two simultaneous products, i.e., Fe-N@CDs (0 D fluorescent carbon dots) and Fe3O4-CDs (magnetic nanoparticles) in a single step hydrothermal carbonization process by using a sole iron salt (FeCl2) and carbon precursor (citric acid) in the presence of ethylenediamine is reported. The as prepared Fe-N@CDs selectively detect doxycycline with a limit of detection value of 66 ng mL-1 and in the linear range from 0 mg mL-1 to 50 mg mL-1, whereas the other formed products, i.e., Fe3O4-CDs, degrade doxycycline by 70.26% in just 5 min by applying shear force using simply a kitchen blender. The results demonstrated the suitability and application scope in food and environment safety.

N Itrogen-Doped Carbonized Polyaniline (N-Cpani) for Peroxydisulfate (Pds) Activation Towards Efficient Degradation of Doxycycline (Dox) Via the Non-Radical Pathway Dominated by Electron Transfer

N Itrogen-Doped Carbonized Polyaniline (N-Cpani) for Peroxydisulfate (Pds) Activation Towards Efficient Degradation of Doxycycline (Dox) Via the Non-Radical Pathway Dominated by Electron Transfer

Mechanochemical Synthesis of La-Sr-Co Perovskite Composites for Catalytic Degradation of Doxycycline in the Dark: The Role of Oxygen Vacancies

Mechanochemical Synthesis of La-Sr-Co Perovskite Composites for Catalytic Degradation of Doxycycline in the Dark: The Role of Oxygen Vacancies

Subsurface and solid solution-type defect engineering in the CoCr2O4–Bi2WO4–NiS2 nanocomposite for the visible-light degradation of doxycycline and removal of chromium and its genotoxic evaluation in Allium cepa

The double Z-scheme subsurface and solid solution-type defect engineering in CoCr2O4–Bi2WO4–NiS2 nanocomposite allow it to be used for the treatment of contaminated environmental water.

Electrochemical Degradation of Doxycycline in a Three-Dimensional Vermiculite/Peroxymonosulfate Electrode System: Mechanism, Kinetics, and Degradation Pathway

Electrochemical Degradation of Doxycycline in a Three-Dimensional Vermiculite/Peroxymonosulfate Electrode System: Mechanism, Kinetics, and Degradation Pathway

Green synthesis of manganese–cobalt–tungsten composite oxides for degradation of doxycycline via efficient activation of peroxymonosulfate

The advanced oxidation process of peroxymonosulfate activated by solid catalyst is one of the main technologies to solve the pollution of antibiotics in water environment.In this work, a series of composites (MCW) containing Mn, Co, and W were synthesized using green ball milling, which does not produce the three wastes (waste gas, waste water and industrial residue). It shows a unique and high catalytic activity for peroxymonosulfate-based degradation of doxycycline (DC) under the pH condition between 4 and 9, and it can be reused five times. MCW composites remove DC using singlet oxygen and superoxide free radicals, as well as a large number of oxygen vacancies for electron storage. The formation rate of free radicals is determined by the conversion rates of Mn3+/Mn2+ and Co3+/Co2+. In addition, there are three ways to degrade DC to form 18 kinds of intermediates, and the toxicity of all the intermediates were predicted by ECOSAR program. The highly active catalysts obtained using a green synthetic route for the activation of peroxymonosulfate show a great potential for decontamination of antibiotics wastewater.