Oxidation Of Tetracycline Research Articles

Enhanced electrochemical oxidation of tetracycline and atrazine on SnO2 reactive electrochemical membranes by low-toxic bismuth, cerium doping

SnO2-Sb electrodes are widely used in electrochemical advanced oxidation processes for water treatment; however, the release of highly toxic Sb3+/Sb5+ has aroused environmental concern. This study systematically investigated the potential of Bi and Ce elements as substitutes to fabricate doped-SnO2 reactive electrochemical membrane (REM) for water purification. Compared with the control (SnO2-Sb-REM), SnO2-Bi-REM showed a higher direct electron transfer (DET) rate and •OH yield due to its larger electroactive surface area. The higher oxygen evolution potential of SnO2-Ce-REM enhanced selectivity for •OH generation. Although both SnO2-Bi-REM and SnO2-Ce-REM exhibited higher electrooxidation of tetracycline hydrochloride (TCH) and atrazine (ATZ) than SnO2-Sb-REM, only the service lifespan of SnO2-Bi-REM can meet the requirements of practical applications. Mechanistic studies of the degradation pathways indicated that the rapid degradation of TCH on SnO2-Bi-REM was mainly contributed by the DET process, while the transformation of intermediates involved the reactions with •OH. In comparison, aqueous •OH played an important role in the degradation of refractory ATZ. Moreover, a SnO2-Bi-REM system demonstrated ∼99% removal of trace TCH and ATZ from wastewater effluent in single-pass operation at a low electrical efficiency per log order removal (EE/O, 0.71 kWh m−3). To this end, the SnO2-Bi-REM is demonstrated to be a promising electrode to replace SnO2-Sb-REM for efficient and sustainable water purification.

Photo-deposition of Ag/AuNPs on TiO2 accelerating the oxidation of tetracycline under visible light

Photo-deposition of Ag and AuNPs at different compositions on TiO2 was performed under UV-light to yield TiO2@Ag(100), TiO2@Au-Ag(25:75), TiO2@Au-Ag(50:50), TiO2@Au-Ag(75:25), TiO2@Au(100). Photo-deposition of Ag/Au NPs on TiO2, which is limited in literature, was performed to control the size of NPs on TiO2, agreeing with the surface area. The formation of small Ag or AuNPs on TiO2 was obtained through non-epitaxial growth on TiO2NPs. TiO2@Ag/AuNPs, absorbing the visible light and are employed to oxidize tetracycline and analyzed the intermediate formation. Cell images of the samples were explored.

Multiple roles of hydroxylamine for degradation of tetracycline in HA/Fe-Al2O3/O3 process

Hydroxylamine (HA) and a heterogeneous catalyst Fe-Al2O3 prepared by the soak-calcination method were induced in the oxidation of tetracycline (TC) by ozone. The maximum 75.2% removal efficiency of total organic carbon (TOC) was achieved after 30 min of reaction at O3 flow rate 0.2 L/min, HA concentration 0.9 mM, dosage of Fe-Al2O3 6.6 g/L, and initial pH 4.8. The results indicated that TC was mainly degraded by ozone oxidation catalyzed with HA and Fe-Al2O3, where HA played multiple vital roles. HA not only catalyzed the oxidation of ozone, but also reduced Fe(III) to enhance the removal of pollutant. However, HA could also exhibit an inhibiting effect by consuming OH when initial pH was above 4.5. The catalysis of Fe3+/Fe2+, Fe-Al2O3 adsorption, and ozone direct oxidation also contributed to the degradation of TC. The electron paramagnetic resonance (EPR) result showed that OH was the main active substance in the HA/Fe-Al2O3/O3 system. In addition, the possible degradation pathways were proposed. The acute toxicity of wastewater treated with the HA/Fe-Al2O3/O3 system was less than the untreated wastewater. Overall, this study illustrates combination of HA and Fe-Al2O3 to catalyze ozonation is an efficient method to treat antibiotic wastewater.

Photocatalytic oxidation of tetracycline, reduction of hexavalent chromium and hydrogen evolution by Cu2O/g-C3N4 S-scheme photocatalyst: Performance and mechanism insight

An efficient Step-scheme heterojunction of Cu2O/g-C3N4 catalyst was synthesized and used in the degradation of pollutants and energy generation. Among the as-synthesized catalysts, 1-Cu2O/g-C3N4 showed the highest catalytic activity, the photocatalytic reduction efficiency of Cr6+ and the photocatalytic oxidation efficiency of tetracycline (TC) were 77.7% and 95.1%, respectively. The highest H2 production rate for the 1-Cu2O/g-C3N4 sample was 480.6 μmol g−1.h−1, which is 12 times that of a pristine Cu2O sample. The Cu2O/g-C3N4 catalyst showed satisfactory stability and perfect photocatalytic performance, which was attributed to the efficient interfacial charge separation and the formation of Step-scheme heterojunction photocatalyst retaining strong photocatalytic oxidation and reduction capabilities. Importantly, the charge density difference of Cu2O/g-C3N4 composite sample was simulated, which suggestedthat a built-in electric field was formed, it was helpful for fabricating the Step-scheme heterojunction structure between g-C3N4 and Cu2O.

Oxidation of tetracycline antibiotics by peracetic acid: Reaction kinetics, mechanism, and antibacterial activity change

Peracetic acid (PAA) is an emerging oxidant and disinfectant increasingly used in wastewater treatment. Tetracyclines (TCs) are extensively consumed antibiotics, and frequently detected in the wastewater and surface water. Herein, PAA was found to show high reactivity towards TCs for the first time. This reaction follows the second-order kinetics with the rate constant (k2,app) rapidly raised from pH 5 to 7, and then slightly increased to pH 9. Degradation of TCs by PAA was slightly influenced by water components, thus maintaining high efficiency in the real waters. Theoretical calculations revealed the electrons mainly concentrated on the B-ring of TCs, implying the B-ring as the reactive moieties for PAA oxidation. Transformation product analysis confirmed that oxidation of TCs by PAA mainly proceeded via hydroxylation and N-demethylation. Finally, PAA-promoted oxidation could remarkably reduce the antibacterial activity of TCs.

New insight into transformation of tetracycline in presence of Mn(II): Oxidation versus photolysis

Tetracycline (TC) and Mn(II) is a common antibiotic and metal ion respectively. Nevertheless, literatures involving in the effects of Mn(II) on TC transformation are still insufficient. In this study, the kinetic experiment, spectral analysis, complexation experiment and electrochemical analysis, theoretical calculation and products detection were carried out to probe into oxidation and photolysis of TC with Mn(II). Mn(II) greatly accelerated TC oxidation, preferably tending to complex with TC at O10 – O12 or O2 – O3 site. There were a TC-Mn(II)/TC-Mn(III) redox couple and electron transfer process. Conversely, Mn(II) inhibited photolysis of TC. The photolysis of excited TC could compete with energy dissipation reactions. The electron transfer and complexation reaction easily made excited TC energy transfer, thus slowing down photolysis process. During the TC transformation, the intensity of functional groups was significantly decreased. Simultaneously, the degradation pathways mainly included eight reactions. It is a very interesting and probably overlooked phenomenon, which identifies new transformation of TC with Mn(II). This study helps to further understand fate and environmental behavior of antibiotics and metal ion.

Activation of peroxydisulfate by magnetically separable rGO/MnFe2O4 toward oxidation of tetracycline: Efficiency, mechanism and degradation pathways

• As-synthesized rGO/MnFe 2 O 4 can activate PDS to effectively degrade TC. • Activation mechanism of PDS and degradation pathway of TC were proposed. • The carbonyl group in rGO participated in the activation of PDS. • The 1 O 2 played a main role in the degradation of TC. • TC degradation in actual water matrices was studied. Peroxydisulfate (PDS) activation by a novel magnetically recoverable reduced graphene oxide (rGO)/MnFe 2 O 4 composite was studied for the removal of tetracycline (TC), a widely used antibiotic. The catalytic performance of rGO/MnFe 2 O 4 was greatly higher than that of bare MnFe 2 O 4 , and the degradation rate of TC tended to be raised as the content of rGO in composite catalyst increased. After reaction for 80 min, the optimized rGO/MnFe 2 O 4 -15 catalyst can degrade 90.1% of TC in water (20 mg/L) with the addition of 1.5 g⋅L −1 PDS. The effect of PDS dose, temperature, initial pH, inorganic anions and humic acid on TC removal was also examined. The quenching experiments and electron paramagnetic resonance (EPR) tests suggested that the radical (SO 4 •− and ∙ OH) and non-radical ( 1 O 2 ) oxidation processes worked together for the degradation of TC in rGO/MnFe 2 O 4 -PDS system. PDS was activated to produce SO 4 •− by MnFe 2 O 4 , and rGO can donate electron to facilitate the redox cycle of ≡M(II)/≡M(III) (M refers to Mn or Fe), thus promoting the formation of SO 4 •− . The carbonyl group in rGO participated in the activation of PDS to generate 1 O 2 . The linear sweep voltammetry indicated that rGO/MnFe 2 O 4 did not act as an electronic medium to promote the electron transfer from TC to PDS. The degradation products were identified by LC–MS and the possible degradation pathways of TC were put forward. Furtherly, the decontamination of natural actual water (tap water, secondary effluent and river water) spiked with TC were evaluated.

Synthesis of magnetic nanocomposite Fe3O4@ZIF-8@ZIF-67 and removal of tetracycline in water.

We prepared a double-layer magnetic nanocomposite Fe3O4@ZIF-8@ZIF-67 by layer-by-layer self-assembly. Fe3O4@ZIF-8@ZIF-67 was used to remove tetracycline from an aqueous solution via a combination of adsorption and Fenton-like oxidation. Depending on the outstanding porous structure of the Fe3O4@ZIF-8@ZIF-67, a high adsorption capacity for tetracycline was 356.25mgg-1, with > 95.47% removal efficiency within 100min based on Fenton-like oxidation. To better understand the mechanisms involved in integrated adsorption and Fenton-like oxidation, various advanced characterization techniques were used to monitor the changes in morphology and composition of Fe3O4@ZIF-8@ZIF-67 before and after removal of tetracycline. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) all supported adsorption and Fenton oxidation of tetracycline. This study extends the application of Fe3O4@ZIF-8@ZIF-67 for environmental remediation.

Cyano-bridged Schottky junction of CN-TiC for enhanced photocatalytic H2 evolution and tetracycline degradation

The electron collection and accumulation at carbon nitride (CN) surfaces play critical roles in coupling multielectron processes with carriers' dynamics for boosting tetracycline (TC) degradation, where MXenes are excellent candidates for tailoring carriers' dynamics in CN. Cyano-intermediated heterojunctions between CN and titanium carbide (CN-TiC) were synthesized via TiC-assisted thermopolymerization. Mesoporous morphology and combination of two materials were confirmed. Investigations on optical properties indicate that cyano groups were formed via this TiC-assisted polymerization, leading to strong chemical-physical interaction for intimate hetero-contact and enhanced visible absorption. As results, the optimized CN-TiC shows improved TC degradation rate (k = 0.05292 min−1), 3.5 times higher that of CN (k = 0.0153 min−1) or 176 times that of TiC (0.0003 min−1). Kinetics investigations reveal that superoxide radicals (.O2–) dominate TC oxidation, where TiC facilitates electrons' transportation/collection. Further photochemical investigations and band analysis suggest that the formation of Schottky junction between CN and TiC promotes electron-hole separation/transportation and electrons' accumulation for boosting TC degradation. We expanded this design to photocatalytic H2 evolution (PHE) or rhodamine degradation, achieving the PHE rate of 1941 μmol·g−1·h−1 or rhodamine removal ratio of 96%, far higher than that of CN.

A highly efficient perovskite oxides composite as a functional catalyst for tetracycline degradation

• A steady heterojunction interface between Bi 4 Ti 3 O 12 and LaCoO 3 was exquisitely constructed for the boosting oxidation of tetracycline. • A direct Z-scheme heterostructure with highly efficiency electron transport capability can be founded in this heterojunction. • This heterojunction system between Bi 4 Ti 3 O 12 and LaCoO 3 is first applied for the photocatalytic oxidation of tetracycline. • The degradation activity of LCBT-2 for SMX reaches 87.8% (100 min) and its stability can maintain 78.4% even after 4 cycles. Of large amounts of catalysts that have been developed to date for high catalytic activity and durability, perovskite oxides have appealed the attention due to their inherent performance as well as structural flexibility. Especially, the aurivillius perovskites could be a fantastic “pollutants oxidizer”. Therefore, we designed a novel catalyst, LCBT-2 (LaCoO 3 :Bi 4 Ti 3 O 12 = 1:2, mole ratio), composed by ultrathin aurivillius perovskite Bi 4 Ti 3 O 12 nanosheets and typical perovskite LaCoO 3 particles. This new type of composite catalyst appeared exceptional catalytic activity and high stability for tetracycline (TC) degradation. The activity of TC degradation by LCBT-2 reached 87.8% and the activity could maintain 78.4% after 4 cycles, proving the high durability of LCBT-2. A proposed mechanism for the synergistic effects between Bi 4 Ti 3 O 12 and LaCoO 3 was analyzed by active species trapping experiment and electron paramagnetic resonance (EPR). Moreover, the possible pathways of TC degradation were proposed according to the results of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). This study aims at the application of coupled perovskite oxides as photocatalysts for TC degradation and reveals the reason of synergistic effects between the two part of perovskite oxides (Z-scheme heterojunction interface) by experiments and in-depth mechanistic analysis.

A high-performance electrochemical sensor for sensitive detection of tetracycline based on a Zr-UiO-66/MWCNTs/AuNPs composite electrode.

Herein, a high-performance electrochemical sensor was constructed based on a metal-organic framework (Zr-UiO-66)/multi-carbon nanotubes/gold nanoparticles (Zr-UiO-66/MWCNTs/AuNPs) composite modified glassy carbon electrode for sensitive determination of tetracycline. The morphology, structure, and performance of Zr-UiO-66/MWCNTs/AuNPs were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and electrochemical techniques. The Zr-UiO-66/MWCNTs/AuNPs nanohybrids exhibited excellent electrocatalytic activity towards the oxidation of tetracycline, mainly because of the synergistic effect of the MOFs, MWCNTs, and gold nanoparticles. The electrochemical kinetics and catalytical mechanism of tetracycline were demonstrated, proving that tetracycline's electrocatalytic oxidation reaction was an absorption-controlled two-step process involving the transfer of two protons and two electrons, respectively. Furthermore, a simple and facile method was used to achieve the regeneration of the absorbed saturated electrode. A low concentration of tetracycline was detected by amperometry with the linear ranges of 5 × 10-7 to 2.25 × 10-4 mol L-1 (R2 = 0.9941), the sensitivity was 45.4 mA L mol-1, and the limit of detection was as low as 1.67 × 10-7 mol L-1 (S/N = 3). In addition, the composite electrode demonstrated high selectivity (interference deviation of ± 5%), satisfactory reproductivity (RSD of 5.31%), and long-term stability (easy regeneration) and was successfully applied in the analysis of tetracycline antibiotics in actual samples. Thus, the proposed electrode provides a promising and prospective MOFs-based sensing platform for the detection of tetracyclines in the environment.

Stable and magnetically separable nanocomposite prepared from bauxite mining tailing waste as catalyst in wet peroxidation of tetracycline

The purpose of this study is to convert bauxite mining tailing waste into magnetic nanocomposite as catalyst in catalytic wet peroxidation of tetracycline. The preparation of material was performed via hydrothermal method of immobilized iron oxide precursor of Fe2+ and Fe3+ in alkaline condition, followed by calcination. The obtained nanocomposite was characterized using X-ray diffraction, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and vibration sample magnetometer. The results from XRD, XPS and TEM analyses showed that the composite composed as the dispersed γ-Fe2O3 in combination with Fe3O4 nanoparticles. The catalytic activity studies of the nanocomposite showed the capability of material to remove tetracycline with supportive adsorption capability. The oxidation of tetracycline was recorded to follow pseudo-first kinetics with removal efficiency of 89.7 % for 20 ppm of tetracycline. Insignificant change of removal efficiency at varied tetracycline concentration ranging at 2–40 ppm indicated its potential to be active in wide range of concentration. In addition, the nanocomposite showed stability as studied by XRD analysis along with the easy in separation as the magnetic properties with magnetism of 9.8 emu/g.

In-Depth Insight into the Mechanism on Photocatalytic Selective Co2 Reduction Coupled with Tetracycline Oxidation Over Bio1- X Br/G-C3n4

In-Depth Insight into the Mechanism on Photocatalytic Selective Co2 Reduction Coupled with Tetracycline Oxidation Over Bio1- X Br/G-C3n4

A Dual Defect Comodified S-Scheme Heterojunction for Boosting Photocatalytic Co2 Reduction Coupled with Tetracycline Oxidation

A Dual Defect Comodified S-Scheme Heterojunction for Boosting Photocatalytic Co2 Reduction Coupled with Tetracycline Oxidation

Dual Mofs Heterojunction: Mil-53 Coated with Amorphous Uio-66 for Enhanced Photocatalytic Oxidation of Tetracycline and Methylene Blue

Dual Mofs Heterojunction: Mil-53 Coated with Amorphous Uio-66 for Enhanced Photocatalytic Oxidation of Tetracycline and Methylene Blue

In-Situ Immobilization of Ag/Agcl on Sulfurized G-C3n4 Nanosheet for Enhancing Visible-Light Driven Photocatalysis Toward Simultaneous Oxidation of Tetracycline and Reduction of Cr(Vi) in Water

In-Situ Immobilization of Ag/Agcl on Sulfurized G-C3n4 Nanosheet for Enhancing Visible-Light Driven Photocatalysis Toward Simultaneous Oxidation of Tetracycline and Reduction of Cr(Vi) in Water

Enhanced Electrochemical Oxidation of Tetracycline and Atrazine on Sno2 Reactive Electrochemical Membranes by Low-Toxic Bismuth, Cerium Doping

Enhanced Electrochemical Oxidation of Tetracycline and Atrazine on Sno2 Reactive Electrochemical Membranes by Low-Toxic Bismuth, Cerium Doping

Simultaneous photocatalytic tetracycline oxidation and chromate reduction via a jointed synchronous pathway upon Z-scheme Bi12O17Cl2/AgBr: insight into intermediates and mechanism

A 2D/0D Bi12O17Cl2/AgBr Z-scheme photocatalyst provides a jointed synchronous pathway for simultaneous Cr(vi) and TC removal.

Shell-core MnO2/Carbon@Carbon nanotubes synthesized by a facile one-pot method for peroxymonosulfate oxidation of tetracycline

• MnO 2 /C@CNT for PMS activation was fabricated via a facile one-pot method. • Increased Mn (III)/Mn (IV) and surface –OH are the basis for high catalytic activity. • SO 4 · - and · OH play dominant roles in TC degradation in the MnO 2 /C@CNT-PMS system. • The toxicity of solution finally decreased after the MnO 2 /C@CNT-PMS process. In this study, a new type of MnO 2 /carbon@carbon nanotubes (MnO 2 /C@CNT) shell-core nanohybrid for peroxymonosulfate (PMS) activation was synthesized by a one-pot method, which simultaneously achieved the synthesis of MnO 2 and assembly of components. Tetracycline (TC) degradation by MnO 2 /C@CNT-PMS was enhanced obviously, and MnO 2 /C@CNT (1.75:1)-PMS systems exhibited the best TC degradation efficiency (85.6%) at 10 min. In addition, the effects of catalyst dosage, PMS dosage, initial pH, reaction temperature, and co-existing ions on the degradation of TC were investigated. The stripping and insertion of the nanocarbon during the synthetic process were the basis for the enhancement of the Mn (III)/Mn (IV) ratio and surface –OH groups, which further accelerated electron transfer and the conversion of Mn and O species. EPR analysis along with the free-radical quenching experiments confirmed the presence of SO 4 · - and · OH during the catalytic reaction, among which SO 4 · - was the main active specie. Moreover, a comprehensive toxicity assay and prediction were performed based on bioluminescence inhibition experiments and the Ecological Structure Activity Relationships (ECOSAR) program. Finally, reasonable degradation pathways of TC were proposed based on LC-MS analysis.

Design and controllable preparation of Bi2MoO6/attapulgite photocatalyst for the removal of tetracycline and formaldehyde

Herein, based on the natural attapulgite nanofibers and bismuth molybdate photocatalyst, a composite photocatalyst with a unique structure was designed and prepared via a simple solvothermal method. Compared with pure Bi2MoO6, Bi2MoO6/attapulgite had stronger formaldehyde and tetracycline treatment ability. The tetracycline oxidation reaction rate constant and formaldehyde mineralization rate using Bi2MoO6/attapulgite catalyst was 0.0109 min−1 and about 58%, respectively, which was about 1.70 times higher than that of pure Bi2MoO6, respectively. The introduction of attapulgite improved the adsorption performance of Bi2MoO6/attapulgite, increased the light-receiving area and active sites, thus ameliorated the mass transfer efficiency and photon efficiency in the reaction process. The material showed excellent reusability and environmental adaptability and has good application potential. This study proposed a high application prospect of organic waste gas and wastewater treatment technology.