Removal Of Tetracycline Antibiotics Research Articles

Eco-inspired synthesis of MgO-infused g-C3N4 nanocomposites from tulsi seeds for advanced photocatalytic environmental remediation.

This study introduces a novel approach to synthesizing magnesium oxide (MgO) nanoparticles through the use of Ocimum sanctum (tulsi seed) extract combined with the thermal polymerization of MgO-doped graphitic carbon nitride (MgCN) nanocomposites. The nanocomposites were prepared at varying MgO concentrations (0.5 mM, 1.0 mM, 1.5 mM, and 2.0 mM) to optimize their properties. Comprehensive characterization of the synthesized MgO nanoparticles and MgCN nanocomposites was conducted using advanced analytical techniques, including UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray mapping (SEM-EDX), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The MgCN nanocomposite with 1.5 mM MgO demonstrated a high surface area of 98.287 m2 g-1, as determined by Brunauer-Emmett-Teller (BET) analysis. X-ray photoelectron spectroscopy (XPS) confirmed the presence of carbon and nitrogen elements, validating the integration of MgO into the nanocomposite matrix. High-resolution transmission electron microscopy (HRTEM) images depicted planar, stacked, and wrinkled structures characteristic of a graphitic-like material. Consistent with a Z-scheme heterojunction, the MgCN (1.5 mM) sample exhibited an enhanced morphology, increased surface area, improved visible light absorption, and reduced band gap. This particular nanocomposite displayed remarkable adsorption and photocatalytic degradation capabilities, achieving up to 98% removal of methylene blue and 54% removal of tetracycline antibiotics. Furthermore, it showed significant antibacterial activity against Escherichia coli. Notably, the MgCN (1.5 mM) nanocomposite maintained its performance over four cycles, underscoring its potential for sustained application in wastewater treatment and the elimination of organic contaminants. The scavenging activity of the nanocomposites was also explored, revealing additional environmental benefits. This research highlights a promising pathway for developing eco-friendly nanocomposites with robust capabilities in water purification and pollution control.

Sheet-like graphitized glucose-based mesoporous carbon for aqueous adsorption of tetracycline antibiotic

Antibiotics are an emerging water pollutant without universally agreed regulations. Hence, its removal from the water will minimize antibiotics resistance bacteria. Herein, facile pyrolysis at 500 °C for 3 h was deployed to convert d-glucose to sheet-like graphitized carbon (GLU-500) for the removal of tetracycline antibiotics. The carbon material was characterized and the effect of pH, contact time, and initial concentration of tetracycline was elucidated. Results revealed that pyrolysis temperature tailored the morphology, functional group, and textural characteristics to accumulate a high amount of tetracycline. Electrostatic attraction at a pH of 5 favored the highest removal of 138.32 mg g−1of tetracycline at 30 °C, however, this adsorption capacity declined at increasing pH due to the formation of zwitterions that imposes a diffusion barrier. A multilayer adsorption was observed for the tetracycline-GLU-500 system, which was best described by Freundlich isotherm with R2 of 0.94−0.99. Also, the pseudo-second-order kinetic model confirms that thetetracycline-GLU-500 system adsorption is mainly by chemical interaction. The study confirms that abundant glucose can be a sustainable precursor for treatment of antibiotics contaminated water.

Dual Z-scheme Pr2Sn2O7/P@g-C3N4/SnS2 heterojunctions for the removal of tetracycline antibiotic by persulfate activation: Kinetics, thermodynamic parameters, density functional theory, and toxicity studies

In this study, a Pr2Sn2O7/P@g-C3N4/SnS2 ternary nanocomposite photocatalyst is obtained by hydrothermal synthesis followed by mechanical grinding. By separating electrons and holes (e−/h+) effectively through the dual Z-scheme heterojunction and activating persulfate (PS), the heterojunction demonstrated superior visible light-driven catalytic activity. Tetracycline (TC) was degraded (89.48%) in 60 min using 30 mg/L of ternary composite and 30 mg/L of PS. This system displayed the highest pseudo-first-order kinetic constant (0.0989 min−1 and R2 = 0.969). The electron paramagnetic resonance analysis showed that SO4−, OH, O2−, and 1O2 were involved in TC degradation. TC's vulnerability positions and degradation pathways were analyzed using DFT and gas chromatography-mass spectrometry analysis, while toxicity assessment software was used to determine the toxicity of intermediate products. Thus, Pr2Sn2O7/P@g-C3N4/SnS2 was established to be a promising photocatalyst template for pollutant remediation.

Hydrothermal synthesis of Z-scheme photocatalyst Zn2SnO4-g-C3N4 for efficient tetracycline antibiotic removal

Photocatalysis is a promising green technique to eliminate pollutants for environmental remediation so that the design of proficient photocatalyst stands on the cutting edge of material science. In this work, the visible light-responsive Zn2SnO4-g-C3N4 (ZSC) photocatalyst is synthesized using a simple one-step hydrothermal method without any surfactant. The physical and chemical characteristics of the synthesized composites are investigated. The ZSC composites demonstrate significant improvement in visible-light driven photocatalytic performance towards the degradation of tetracycline antibiotics. The formation of a Z-scheme heterojunction plays a crucial role in enhancing the photocatalytic performance of the composites. This work provides the design and preparation of direct Z-scheme photocatalysts using a simple hydrothermal method for environmental remediation.

Novel g-C3N4/PrFeO3 nanocomposites with Z-scheme structure and superior photocatalytic activity toward visible-light-driven removal of tetracycline antibiotics

In the presented work, heterostructured nanocomposites based on g-C3N4 and PrFeO3 with different mass content of PrFeO3 (0–10 wt%) were prepared by ultrasonic processing to study their photocatalytic activity in the process of antibiotic degradation under visible light. The study of phase composition, structural, morphological and textural characteristics carried out by powder X-ray diffraction, scanning electron microscopy and adsorption-structural analysis confirmed the presence of two phases - graphite-like C3N4 and orthorhombic PrFeO3 with average crystallite sizes of 5 and 21 nm and mesoporous structure with specific surface area of 57.2–68.6 m2/g and average pore size of 20 nm. The measured values of the forbidden bandwidth for the obtained nanocomposites were ∼3 eV, indicating potential activity under visible light irradiation. The efficiency of antibiotic removal under visible light was evaluated in the degradation of TCHCl. It was found that 5 % PrFeO3 content was optimal and increased the TOF by 5 times compared to pure g-C3N4. The results of photocatalytic test with absorbers showed that photocatalysis occurs by Z-scheme mechanism. The results obtained allow us to consider this nanocomposite as an effective and stable photocatalyst for pharmaceutical wastewater treatment.

Layered bimetallic oxide composite film: A highly efficient and reusable photocatalytic film for removal of tetracycline antibiotics

To fabricate novel photocatalytic materials is critical to the removal of emerging pharmaceutical pollutants from water samples. However, the photocatalytic materials still face the challenges of degradation performance and reusability. Here, layered bimetallic oxide (LBMO) composites were constructed by using hydrothermal synthesis method of layered double hydroxides (LDH) as precursors, and the LBMO films were prepared by dispersing the LBMO composites in poly(acrylonitrile-co-maleic acid) (PANCMA) solution. The obtained LBMO/PANCMA films exhibited high removal efficiency and good reusability for tetracycline (TC) degradation. Under the optimal conditions, the removal rate of LBMO/PANCMA composite film (20 mg) for TC (20 μg/mL) was 99.34 % within 40 min of light exposure, and retain above 85 % of removal rate even after 10 consecutive uses. Moreover, the possible TC degradation pathways were deduced by analyzing the TC degradation intermediates with LC-MS method, and the toxicity evolution of the TC degradation products was appraised by using density functional theoretical (DFT) method. This study provides a simple and feasible synthesis strategy for membrane-based photocatalytical materials to remove environmental pollutions.

Novel bifunctional in-based metal–organic gel/bacterial cellulose composite gels for effective tetracycline antibiotics removal: Synergistic behavior and mechanism insight of adsorption-photocatalysis

The widespread pollution by tetracycline antibiotics has been proved to be a serious problem to human health and biological systems. Synergistic adsorption-photocatalysis method has demonstrated satisfactory miraculous results for the removal of recalcitrant pollutants. Here we constructed a novel bifunctional In-MOG with hierarchical pore structures, large specific areas and abundant active sites via room-temperature synthesis, achieving 92.93% and 95.58% removal of chlortetracycline (CTC) and tetracycline (TTC) in 60 min, respectively. The excellent removal performance was attributed to the synergistic adsorption-photocatalysis process that resembled a repetitive assembly line work of “enriching and destroying” pollutants. Briefly, CTC/TTC molecules in the aqueous environment were rapidly adsorbed by In-MOG through pore filling, electrostatic interaction, hydrogen bonding interaction, complexation and π-π stacking interaction to accomplish enrichment of pollutants; meanwhile, the generated h+ and •O2− were involved as the main active species in the rapid in-situ photodegradation of pollutants to complete their destruction. Furthermore, In-MOG exhibited excellent anti-interference ability and reusability. Afterwards, in order to address the drawback of easy agglomeration and difficult recycle of powdered In-MOG, In-MOG/BC with the advantages of good removal performance and fine stability was constructed by immobilizing In-MOG into bacterial cellulose (BC) flexible substrate. Further exploration of In-MOG/BC in a self-built reactor for CTC/TTC removal from dynamic systems was carried out to assess the prospect for large-scale applications. Overall, the facile rational design for In-MOG/BC with synergistic adsorption-photocatalysis and the continuous flow reactor provides worthwhile insights in the water purification field.

Development of a new promising nanocomposite photocatalyst of polyaniline/carboxylated graphene oxide supported on PVA film to remove different ecological pollutants

The process of removing dye and antibiotic contaminants from wastewater is quite challenged, especially with water shortage crisis. In this study, for the first time a composite of polyaniline (PANI) and carboxylated graphene oxide (CGO) supported on polyvinyl alcohol (PVA) film (PVA/PANI/CGO) was investigated as anticipated nanocomposite film that can be used to promote wastewater treatment. The effectiveness of this nanocomposite film in wastewater treatment was optimized in a batch system for the removal of methylene blue (MB) and tetracycline antibiotic (TC). The presence of CGO proved to be significant in both adsorption and photocatalytic process and assist the photocatalytic activity of PANI. The optimized conditions for photodegradation process were assessed by using a response surface methodology model (RSM). The optimum resulting scores at 25 °C and pH equal 7 for achieving 97.8 removal % for MB were 15.3 mg L−1 initial concentration, with using 2 lamps as a maximum light intensity and weight of film equal 0.02 g. While the optimum conditions for TC removal are; 23.9 mg L−1 initial concentration of TC, with using 2 lamps and weight of film equal 0.017 g to achieve 73.1 removal %. For potential usage in wastewater treatment, the produced nanocomposite film appears to be promising.

Eco-friendly remediation of tetracycline antibiotic from polluted water using waste-derived surface re-engineered silica sand

A new green reactive adsorbent (calcium ferric oxide silica sand (CFO-SS)) made from wastepaper sludge ash and ferric ions was synthesised and shown to remove tetracycline antibiotics (TC) from contaminated water effectively. The synthesised sand was dried at 95 °C, and a series of batch and fixed bed experiments were performed to determine the optimum operating conditions. Results showed that the adsorption capacity of the CFO-SS increases with the concentration gradient between the solid and liquid phases. 0.3 g of the new adsorbent was proven sufficient to remove more than 90% of the TC at a pollutant dose of 50 mg/L in 50 mL of simulated groundwater with an agitation speed of 200 rpm for 3 h. The adsorption isotherm followed the Langmuir isotherm model, with a loading capacity of 21.96 mg/g at pH 7, while the Pseudo second-order model best described the absorption kinetics. The adsorption mechanisms proposed included electrostatic interaction, intraparticle diffusion, hydrogen bonding, and cation-π interactions. Characterisation investigations revealed that the newly precipitated oxides on silica sand play an essential role in TC adsorption support. In fixed-bed experiments, it was discovered that reducing the flow rate and inflow concentration of TC and increasing the sorbent mass significantly extended the lifetime of the produced sorbent in the packed column. The measured breakthrough curves were best fit with the Adams-Bohart and the Clark models, as they provided the highest square root number (R2) values. Finally, considering the efficacy of CFO-SS in TC adsorption performance, it can be noted that the novel synthesised reactive material is an efficient and environmentally friendly material for TC removal, and it presents a potential solution to resolving the challenge of TC-rich groundwater.

Coating magnetic nanoparticles with artificial humic acid derived from rice straw for effective removal of tetracycline antibiotics

Artificial humic acid (AHA), with a lot of functional groups, was prepared from waste rice straw, using a hydrothermal process in this study. The AHA was then loaded with Fe3O4 magnetic nanoparticles to prepare AHA coated magnetic nanosorbent (AHA-Fe3O4) for the adsorption and removal of chlortetracycline (CTC), oxytetracycline (OTC) and tetracycline (TC) from water. Adsorption experiments showed that the AHA coating enriched functional groups on Fe3O4 magnetic nanoparticles, reduced defects that ease of oxidation and agglomeration in water bodies, and increased the Fe3O4 magnetic nanoparticles’ specific surface area. The removal of tetracycline antibiotics (TCAs) from water by AHA-Fe3O4 mainly occurred via chemisorption, and with heat-absorbing spontaneous processes. The adsorption maximum (Qm) of AHA-Fe3O4 for TC, CTC and OTC was increased 1.88-, 1.72- and 1.85-fold, respectively, compared with that of bare Fe3O4 magnetic nanoparticles. A novel magnetic nano-adsorbent AHA-Fe3O4 was prepared, which can be easily separated and recovered from water, and has good adsorption selectivity and regeneration recyclability. It is promising to become a green and efficient water pollutants adsorbent.

Effective removal of tetracycline antibiotics from water by magnetic functionalized biochar derived from rice waste

The effective removal of tetracycline antibiotics (TCs) from water is of great significance and remains a big challenge. In this work, a novel magnetized biochar (magnetic functionalized carbon microsphere, MF-CMS) was prepared by the coupling hydrothermal carbonization and pyrolysis activation of starch-rich rice waste using ZnCl2 and FeCl3 as activators. As the MF-CMS dose was 2.0 g/L, the initial concentration of TCs was 100 mg/L, the removal rates of tetracycline, doxycycline, oxytetracycline, and chlortetracycline were 96.02%, 96.10%, 96.52%, and 85.88%, respectively. The best modeled on pseudo second order, Langmuir adsorption model, and intraparticle diffusion kinetic models suggested that both chemisorption and physisorption occurred in all removal processes, in which chemisorption dominated. TCs were efficiently adsorbed through the combined effects of pore filling, electrostatic attraction, π-π interactions, and complexation reactions of surface functional groups (such as γ-Fe2O3 and FeOOH). The removal rates of TCs after five cycles approximately decreased by 20%. And the cycling and metal ion release experiments of MF-CMS indicated that MF-CMS had good reusability, stability, and safety. The estimated cost of preparing MF-CMS is 5.91 USD per kg, and 1 kg of MF-CMS (consuming 8 kg of waste rice) can approximately treat 0.55 tons of TCs wastewater. Overall, the magnetic biochar derived from starch-rich rice waste as an adsorbent has promising and effective for the removal of TCs from water, but also provides a new idea for the resourceful treatment of solid waste.

An ion-coordination hydrogel based sensor array for point-of-care identification and removal of multiple tetracyclines

Misuse and overuse of tetracycline antibiotics (TCs) brings serious issues to ecological environment, food safety and human health. It is urgent to develop unique platform for high efficient identification and removal of TCs. In the present investigation, an effective and simple fluorescence sensor array was constructed based on the interaction between metal ions (Eu3+ and Al3+) and antibiotics. Benefiting from the different affinities between the ions and TCs, the sensor array can identify TCs from other antibiotics, which also can further differentiating four kinds of TCs (OTC, CTC, TC and DOX) from each other via linear discriminant analysis (LDA) technique. Meanwhile, the sensor array performed well in quantitative analysis of single TC antibiotic and differentiation of TCs mixtures. More interestingly, Eu3+ and Al3+-doped sodium alginate/polyvinyl alcohol hydrogel beads (SA/Eu/PVA and SA/Al/PVA) were further constructed, which can not only identify the TCs but simultaneously remove the antibiotics with high efficiency. The investigation provided an instructive way for rapid detection and environment protection.

Comparative adsorption of tetracycline onto unmodified and NaOH-modified silicomanganese fumes: Kinetic and process modeling

Silicomanganese fumes (SMF) are industrial waste and a potential low-cost adsorbent for the removal of contaminants from water. In this study, the adsorption performance of SMF and NaOH-modified SMF (SMF-Na) for the removal of tetracycline (TC) from an aqueous solution was investigated. The characterization results showed the presence of functional groups (SiO2, -OH and C-O-C), a considerably higher surface area of the SMF-Na (142.59 m2 g−1) compared to the SMF (7.73 m2 g−1). The TC adsorption was favored under acidic conditions (pH 2–3) and increased with an increasing amount of adsorbent. The adsorption equilibrium was achieved in 360 min, and the presence of Na+ ions insignificantly influenced the TC adsorption. The Avrami model fitted better to the kinetic data with R2 = 0.995. The isothermal data was well represented by the Redlich-Peterson and Langmuir model. The maximum monolayer adsorption capacity of SMF and SMF-Na was 117 and 129 mg g−1, respectively. The thermodynamic results confirmed that the TC adsorption was endothermic and predominantly governed by physical forces. The removal of TC onto SMF and SMF-Na was maintained above 90 % even after five regeneration cycles The results suggested that SMF-Na is a promising alternative adsorbent for the removal of tetracycline antibiotics from wastewater streams.

Functionally-designed floatable amino-modified ZnLa layered double hydroxides/cellulose acetate beads for tetracycline removal: Performance and mechanism

The over-reliance on tetracycline antibiotics (TC) in the animal husbandry and medical field has seriously affected the safety of the ecological environment. Therefore, how to effectively treat tetracycline wastewater has always been a long-term global challenge. Here, we developed a novel polyethyleneimine (PEI)/Zn-La layered double hydroxides (LDH)/cellulose acetate (CA) beads with cellular interconnected channels to strengthen the TC removal. The results of the exploration on its adsorption properties illustrated that the adsorption process exhibited a favorable correlation with the Langmuir model and the pseudo-second-order kinetic model, namely monolayer chemisorption. Among the many candidates, the maximum adsorption capacity of TC by 10 %PEI-0.8LDH/CA beads was 316.76 mg/g. Apart from that, the effects of pH, interfering species, actual water matrix and recycling on the adsorption of TC by PEI-LDH/CA beads were also analyzed to verify their superior removal capability. The potential for industrial-scale applications was expanded through fixed-bed column experiments. The proven adsorption mechanisms mainly included electrostatic interaction, complexation, hydrogen bonding, n-π EDA effect and cation-π interaction. The self-floating high-performance PEI-LDH/CA beads exploited in this work provided fundamental support for the practical application of antibiotic-based wastewater treatment.

Investigation of the Effectiveness of Tetracycline Antibiotic Removal from Aqueous Solutions by Photo-Fenton Process using Biosynthesized Silver Nanoparticles

Introduction: Tetracycline is an antibiotic that is widely used around the world. Advanced oxidation processes are used for the degradation of resistant organic pollutants in aqueous solutions due to their high oxidation potential. This study aimed to estimate the performance of the ultraviolet rays/hydrogen peroxide/silver nanoparticles (UV/Ag/H2O2) in removing tetracycline antibiotics. Method: In this study, the degradation of tetracycline by the UV/Ag/H2O2 process was investigated under various conditions. The effects of different parameters, such as silver nanoparticles (1, 2, 4, and 6 mM), hydrogen peroxide concentration (10, 30, 50, 80, and 100 mM), pH (4, 7, and 10), and initial antibiotic concentration (15, 30, 45, and 60 mg/L) were investigated in the degradation of tetracycline. Finally, the antibacterial property of the synthesized nanoparticle was determined. Results: Under optimal conditions, within 90 min, the efficiency of tetracycline removal reached above 85% following pseudo-first-order kinetics. The obtained optimum conditions were as follows: tetracycline concentration (15 mg/L), oxidant concentration (80 mM), silver catalyst concentration (4 mM), and pH equal to 4. The size and morphological properties of nanoparticles were assessed by TEM, which showed that particles had a spherical shape with a diameter of about 1-50nm. The biosynthesized nanoparticle had high antibacterial properties. Conclusion: The results of this study showed that green synthesized silver nanoparticles with ultraviolet waves had great catalytic properties for oxidant activation and could also be used to inhibit and destroy resistant bacterial strains

Interfacial configuration and mechanism insights of an all-solid-state Z-scheme BaTiO3/Bi/Bi2O3 heterojunctions for rapid removal of tetracycline antibiotics

Photocatalytic technology based on efficient-economic heterojunction catalysts has been considered a promising approach to remove the discharged tetracycline (TC) antibiotic residues in contaminated water. However, unveiling an effective interface configuration with a clear mechanism is still the toughest challenge for heterojunction photocatalysts. Through a facile route of hydrothermal and heat treatment for the first time, herein, we reported an all-solid-state Z-scheme heterojunction of BaTiO3/Bi/Bi2O3 (BT/Bi/BO) with a conspicuous light response and efficient photo-excited carrier kinetics (high separation and redox ability). It performed a stable and ultrahigh photocatalytic activity toward removing TC, which can be quickly degraded in a few minutes. Density functional theory calculation on heterogeneous interface confirmed that the metallic Bi at the interlayer played a critical role in the excellent photocatalytic performance. The interlayer Bi not only promoted the adhesion between BT and BO to enhance the structural stability, but also had a strong interaction with O atoms of BT to reduce the band gaps to improve the light response. Moreover, its p band located in the band gaps can assist the Z-scheme transfer of photo-excited carriers under an interfacial built-in electronic field of the heterojunction. Therefore, this work provides a new perspective and deep understanding of the configuration and interfacial mechanism of Z-scheme heterogeneous photocatalysts for the removal of antibiotics.

Fabrication and implementation of bimetallic Fe/Zn nanoparticles (mole ratio 1:1) loading on hydroxyethylcellulose – Graphene oxide for removal of tetracycline antibiotic from aqueous solution

Tetracycline (TC) as an antibiotic with high consumption causes the spread of contamination in an aqueous solution. In recent decades, antibiotics are the main cause of hindering the growth of microorganisms. Also, they are one of the important groups of pharmaceuticals with extensive usage in human and veterinary medicine. In the first work of its kind, we used a suitable adsorbent of biodegradable hydroxyethylcellulose (HEC) with graphene oxide (GO) by crosslinking ethylene glycol dimethacrylate (EGDMA) and the Fe/Zn with mole ratio 1:1 bimetallic nanoparticles with HEC-GO support. The materials were identified using FTIR, FE-SEM, EDX, TEM, and TG- DSC analyses. The factors affecting the adsorption process (contact time, initial concentration of TC, solution pH, adsorbent dosage, and reaction temperature) were evaluated in a series of batch systems. The adsorption data showed that the high adsorption capacity was obtained on the HEC-GO and HEC-GO/Fe–Zn (mole ratio 1:1) nanocomposites at pH 3. Also, the contact time as the main factor affecting the adsorption process by adsorbents was investigated and the best contact time was 100 and 20 min. The TC removal percentages of both adsorbents were 85% and 95% for HEC-GO and HEC-GO/Fe–Zn, respectively. The maximum adsorption capacity for TC was evaluated by the isotherm models. The experimental data fitted well with the Langmuir model. In addition, pseudo-first-order, pseudo-second-order, intraparticle diffusion, and the Elovich models were applied to kinetic data. The data indicated that TC adsorption on HEC-GO and HEC–GO/Fe–Zn (mole ratio 1:1) followed the pseudo-second-order kinetic model. The thermodynamic parameters implied that the adsorption process was spontaneous and exothermic. Nano-biocomposite (HEC-GO/Fe–Zn) can be used as an adsorbent to remove water pollutants.

Ultrafast synthesis of laccase-copper phosphate hybrid nanoflowers for efficient degradation of tetracycline antibiotics

The presence of antibiotics in the environment causes increasing attention due to their potential risks to ecosystems and public health. Laccases are versatile oxidases capable of degrading various organic contaminants including pharmaceuticals. However, the performance of bacterial laccases on tetracycline antibiotics (TCs) degradation is seldom investigated. In this work, a bacterial laccase from Bacillus amyloliquefaciens was immobilized as laccase-inorganic hybrid nanoflowers (Lac-hNFs) by a facile and rapid method. The immobilized laccase was employed to remove different TCs including tigecycline, which is a third-generation TC that its degradation by laccase has not been reported. Lac-hNFs were synthesized by sonication-mediated self-assembly of laccase and copper ions in 5 min at room temperature. About 95% of laccase could be encapsulated in the nanoflowers, and the obtained Lac-hNFs exhibited great enhancement in stability under harsh conditions. The immobilized laccase showed a half-life of 11.7 h at 60 °C, which was about 1.4-fold higher than that of the free enzyme. Meanwhile, Lac-hNFs retained 81% of the initial activity after incubation at 25 °C for 10 days. The laccase in combination with acetosyringone could efficiently decompose tetracycline, doxycycline, and tigecycline. More than 79% of the three TCs were transformed in 1 h. Compared with the free enzyme, Lac-hNFs demonstrated higher capacity in the removal of TCs. Furthermore, Lac-hNFs remained their high degradation capacity after five cycles of reuse. Bacterial growth inhibition test revealed that most of the toxicity of TCs was eliminated after Lac-hNFs treatment. The main transformation products were identified by LC-MS, and the possible degradation pathways were proposed. The interaction mechanism between laccase and TCs was also analyzed using molecular docking. This work provides an efficient way to remove toxic organic pollutants.

Removal of tetracycline antibiotics by adsorption and photocatalytic-degradation processes in aqueous solutions using metal organic frameworks (MOFs): A systematic review

• First systematic review on adsorptive and photocatalytic removal of tetracycline antibiotics using MOFs are reviewed. • Tetracycline antibiotics are classified and the characteristics are introduced. • Finally, it is highly reckoned that the application of MOFs in the adsorption/photocatalytic degradation of TCs is worthy of further reviewing. Tetracsyclines (TCs) are a class of antibiotics which could be applied for the treatment of infectious diseases. In fact, the extensive use of TCs has posed serious challenges in the environment. On the other hand, a huge development in the application of metal organic frameworks (MOFs) has been made in recent years due to their wide use in treating contaminants of emerging concern (CECs). In this review, a recent advancement in the application of MOFs for the removal of tetracycline antibiotics by the adsorption and photocatalytic-degradation methods in aquatic solutions is highlighted. It was found out that extensive and successful efforts have been made to efficiently modify MOFs and eventually employ them for obtaining higher level of performance in the adsorption and degradation of antibiotics. The synthesis method, specific surface areas, the ranges and effects of important parameters, mechanisms, removal efficiencies, and the roles of MOFs in the adsorption and photocatalytic removal of TCs were highlighted in details. Moreover, the limitations and possible solutions for each method are discussed. It is reported that the application of MOFs in the adsorption and photocatalytic degradation of TCs in aqueous solutions is assumed to be promising and effective. We finally believe that the application of MOFs in the adsorption/photocatalytic degradation of TCs is worthy of reviewing and hope this review could be useful to the potential readers.

Adsorption and Removal of Antibiotic Pollutants using CuO-Co3 O4 Co-modified Porous Boron Nitride Fibers in Aqueous Solution.

The presence of antibiotic contaminants in aqueous environment already poses significant risks to ecological sustainability, biodiversity and human public health and safety. Therefore, it is urgent to develop practical water pollution control technologies and new materials. Here, we prepared CuO-Co3 O4 co-modified porous boron nitride fibers (P-BNFs) for the adsorption and removal of tetracycline antibiotics (TCs) in aqueous environment. The prepared adsorbents were characterized by XRD, FTIR, XPS, SEM, TEM and BET, and the adsorption behavior was explored by batch experiments. The results show that the removal percentage for doxycycline (DC) reaches 98.68 %, which was much higher than that of P-BNFs, and the modification results of P-BNFs with CuO or Co3 O4 alone. After five regeneration cycles, the removal rate of DC by CuO-Co3 O4 /P-BNFs was still as high as 89.33 %. This is promising and indicates that the prepared CuO-Co3 O4 /P-BNFs adsorbent has good renewable recycling performance and practical application prospects.