Antibiotic Pollution Research Articles

Mn- or Zn-substituted goethite enhancing tetracycline degradation by increasing oxygen vacancies and promoting electron transfer

The metal-substituted goethite with addition of oxidants can effectively promote the degradation of antibiotics, but the usage of external agents restricts its application in in-situ remediation of antibiotic pollution. In this study, the metal-substituted goethites were prepared through co-precipitation method to investigate the effects of using manganese (Mn) or zinc (Zn) substitution alone on tetracycline (TC) degradation, combining with microscopic characterization and electrochemical methods. The results showed that the degradation rate constants of the first stage on Mn or Zn-substituted goethite were 0.299 h-1 and 0.498 h-1, respectively, which were about 2 and 4 times of the pristine goethite (0.117 h-1). In the pH range of 4.0–9.0, Mn or Zn substitution significantly promoted TC degradation. Free and non-free radical pathways existed in the process of TC degradation by Mn or Zn-substituted goethite. The active site change and enhanced electron transfer ability were the main reasons for promoting degradation. Mn or Zn substitution increased oxygen vacancy (OV) content and promoted the electron transfer between TC and goethite. In Zn-substituted goethite, the coupling of OV and electron transfer produced free radicals, and in Mn-substituted goethite, the redox reaction induced mainly by electron transfer produces free radicals. This study reveals a new mechanism of efficient degradation of TC by iron minerals without the need for external oxidants, and the materials studied can be used for in-situ remediation of antibiotic contaminated groundwater.

A Type-II CQDs regulating FeOOH decorated BiVO4 photoelectrode for highly efficient photoelectrochemical degradation of tetracycline

Bismuth vanadate (BiVO4) photoelectrode is of great potentials to be used for photoelectrochemical (PEC) removal of antibiotic pollutant. However, it still suffers from lower efficiency. Herein, a type-II FeOOH-CQDs/BiVO4 photoelectrode was fabricated via the in-situ growth of FeOOH nanoparticles over BiVO4 using Carbon quantum dots (CQDs) as mediator. Benefiting from the type-II heterojunction between BiVO4 and FeOOH, as well as the excellent charger transfer assisted by CQDs, FeOOH-CQDs/BiVO4 exhibited excellent PEC degradation performance towards a typical antibiotic- tetracycline (TC). In a typical PEC process, FeOOH-CQDs/BiVO4 photoelectrode (2 cm × 2 cm) yielded a high removal ratio of ∼ 99 % toward TC within 120 min at an applied potential of 0.6 V (vs. Hg/Hg2Cl2). Moreover, the PEC configuration was verified to be used for TC degradation in actual waters, such as tap water and lake water, with > 90 % of removal ratio. The radical trapping experiments revealed holes and superoxide radical dominated in the TC degradation process. This work provides an insight on the type-II heterojunction photoelectrode to enhance the PEC degradation of TC, which would help for the treatment of antibiotic wastewater.

Facile synthesis of MIL-88A/PVA sponge for rapid tetracycline antibiotics degradation via sulfate radical-advanced oxidation processes

MIL-88A is a metal–organic framework (MOF) material known for its excellent performance in advanced oxidation processes (AOPs). However, due to its powdery nature, MIL-88A may undergo loss during catalytic degradation in flowing solutions, making continuous degradation removal challenging. Herein, we report the synthesis of MIL-88A/PVA sponge composite material by the in-situ integration of MIL-88A with PVA sponge. The composite sponge exhibits excellent removal efficiency of tetracycline antibiotics under the conditions of sulfate radical-advanced oxidation processes (SR-AOPs), achieving a degradation rate exceeding 99.0% within 2 min. Additionally, through fixed-bed column experiments, 1 kg of MIL-88A/PVA can treat 2160 L of wastewater within 24 h, indicating promising industrial applicability. It’s worth noting that this material can be customized into any desired block shape as needed. This work offers a highly promising solution for the application of MOF-based bulk-type catalysts in the treatment of antibiotic pollution using SR-AOPs.

A highly selective Cd‐based metal‐organic framework fluorescent probe for rapid recognition of cephalothin in water

Nowadays, the problem of antibiotic pollution in the water environment is becoming more and more serious, which has caused great harm to human health and the circulatory system. Therefore, it is extremely crucial to design an effective and sensitive method for the recognition of antibiotics in water. In this research, 1‐(4‐carboxyphenyl)‐1H‐pyrazole‐3‐carboxylic acid (H2L) was used as a ligand to prepare a luminescent two‐dimensional (2D) metal–organic framework (MOF), CdL·H2O (1). 1 can specifically recognize antibiotic cephalothin (CET) in aqueous environments through a fluorescence‐enhanced response, which demonstrated a favorable linear correlation between the fluorescence intensities of 1 and the concentrations of CET (0–50 μM) with a linear fluorescence enhancement slope KEC value of 5.4750 × 104 M−1 and a limit of detection (LOD) of 165 nM. The fast response, good selectivity, anti‐interference ability, and reusability for CET recognition were also verified. 1 represents the inaugural MOF‐based fluorescent material designed for the recognition of CET. Additionally, the detection mechanism for CET was explored in detail with a view to better understanding the fluorescence sensing process.

Bacterial dynamics of the plastisphere microbiome exposed to sub-lethal antibiotic pollution

BackgroundAntibiotics and microplastics are two major aquatic pollutants that have been associated to antibiotic resistance selection in the environment and are considered a risk to human health. However, little is known about the interaction of these pollutants at environmental concentrations and the response of the microbial communities in the plastisphere to sub-lethal antibiotic pollution. Here, we describe the bacterial dynamics underlying this response in surface water bacteria at the community, resistome and mobilome level using a combination of methods (next-generation sequencing and qPCR), sequencing targets (16S rRNA gene, pre-clinical and clinical class 1 integron cassettes and metagenomes), technologies (short and long read sequencing), and assembly approaches (non-assembled reads, genome assembly, bacteriophage and plasmid assembly).ResultsOur results show a shift in the microbial community response to antibiotics in the plastisphere microbiome compared to surface water communities and describe the bacterial subpopulations that respond differently to antibiotic and microplastic pollution. The plastisphere showed an increased tolerance to antibiotics and selected different antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs). Several metagenome assembled genomes (MAGs) derived from the antibiotic-exposed plastisphere contained ARGs, virulence factors, and genes involved in plasmid conjugation. These include Comamonas, Chryseobacterium, the opportunistic pathogen Stenotrophomonas maltophilia, and other MAGs belonging to genera that have been associated to human infections, such as Achromobacter. The abundance of the integron-associated ciprofloxacin resistance gene aac(6’)-Ib-cr increased under ciprofloxacin exposure in both freshwater microbial communities and in the plastisphere. Regarding the antibiotic mobilome, although no significant changes in ARG load in class 1 integrons and plasmids were observed in polluted samples, we identified three ARG-containing viral contigs that were integrated into MAGs as prophages.ConclusionsThis study illustrates how the selective nature of the plastisphere influences bacterial response to antibiotics at sub-lethal selective pressure. The microbial changes identified here help define the selective role of the plastisphere and its impact on the maintenance of environmental antibiotic resistance in combination with other anthropogenic pollutants. This research highlights the need to evaluate the impact of aquatic pollutants in environmental microbial communities using complex scenarios with combined stresses.3sW_WiGiki6wh61j1XWikeVideo

Occurrence and distribution of antibiotic pollution and antibiotic resistance genes in seagrass meadow sediments based on metagenomics

Seagrass meadows are one of the most important coastal ecosystems that provide essential ecological and economic services. The contamination levels of antibiotic and antibiotic resistance genes (ARGs) in coastal ecosystems are severely elevated owing to anthropogenic disturbances, such as terrestrial input, aquaculture effluent, and sewage discharge. However, few studies have focused on the occurrence and distribution of antibiotics and their corresponding ARGs in this habitat. Thus, we investigated the antibiotic and ARGs profiles, microbial communities, and ARG-carrying host bacteria in typical seagrass meadow sediments collected from Swan Lake, Caofeidian shoal harbor, Qingdao Bay, and Sishili Bay in the Bohai Sea and northern Yellow Sea. The total concentrations of 30 detected antibiotics ranged from 99.35 to 478.02 μg/kg, tetracyclines were more prevalent than other antibiotics. Metagenomic analyses showed that 342 ARG subtypes associated with 22 ARG types were identified in the seagrass meadow sediments. Multidrug resistance genes and RanA were the most dominant ARG types and subtypes, respectively. Co-occurrence network analysis revealed that Halioglobus, Zeaxanthinibacter, and Aureitalea may be potential hosts at the genus level, and the relative abundances of these bacteria were higher in Sishili Bay than those in other areas. This study provided important insights into the pollution status of antibiotics and ARGs in typical seagrass meadow sediments. Effective management should be performed to control the potential ecological health risks in seagrass meadow ecosystems.

Recycling crayfish shell and waste activated sludge as biochar to in-situ enhance antibiotics removal from wastewater: Linking structure properties and reaction kinetics

Aquaculture water represents a substantial source of antibiotics in the environment, thereby implicating potential hazards to human health and ecological stability. Additionally, the cultivation of crayfish in such water exacerbates concerns regarding the management of shell waste. In this investigation, crayfish shells and waste activated sludge were repurposed as biochar for the in-situ mitigation of antibiotics elimination from aquaculture wastewater. Compared to crayfish biochar (C-BC) solely from crayfish shell, crayfish sludge biochar (CS-BC) significantly enhances the adsorption of typical antibiotics like tetracycline and ciprofloxacin by 50.3–77.1 %. Findings from kinetic and isotherm experiments suggest that antibiotics adsorption mainly involves physical pore filling, but sludge introduction shifts CS-BC towards chemical adsorption. Further analysis reveals that sludge introduction reduces biochar pore size, boosts specific surface area, and offers more active adsorption sites. Additionally, hydrogen bonding on hydroxyl groups and increased oxygen-containing functional groups enhanced antibiotic adsorption onto CS-BC surfaces. This research presents a promising strategy for addressing antibiotic pollution in aquatic environments while also improving the utilization of organic solid waste resources.

Tetracycline degradation through selective activation of molecular oxygen by a fluidic sequential photoelectro-Fenton system

The heterogeneous Fenton-like process is regarded as a promising strategy for reactive oxygen species (ROS) production by driving a two-electron oxygen reduction reaction toward H2O2 and stepping activating the as-generated H2O2 to ROS. Therefore, a fluidic sequential photoelectro-Fenton (PEF) system was developed for the selective activation of molecular oxygen to generate ROS. The system comprises a hydrogen peroxide (H2O2) electrolyzer and a photocatalytic membrane reactor (PCMR). The H2O2 electrolyzer employed a PEI-O/CNT air self-diffusion electrode to achieve high selectivity for H2O2 production without aeration. In the subsequent stage, within the PCMR, two-dimensional Fe/C3N4 with a nanoconfinement structure selectively converted H2O2 into ROS. The exceptional tetracycline (TC) degradation efficiency (96.0 %) was attributable to the synergistic effects of radical and non-radical pathways. The fluidic sequential PEF system achieved efficient and energy-saving H2O2 production (0.134 kWh/g of H2O2) and TC degradation (1.7 kWh/kg of TC). In addition, the PEF system not only has a good effect on removing tetracycline in real water but also can effectively remove a variety of antibiotic pollutants, which has a good prospect for practical application. This research contributed new insights into the development of the fluidic sequential PEF process.

Enhanced Photocatalytic Degradation of Tetracycline by Magnetically Separable g-C3N4-Doped Magnetite@Titanium Dioxide Heterostructured Photocatalyst

Residual drug pollutants in water environments represent a severe risk to human health, so developing a cheap, environmentally friendly, and effective photocatalyst to deal with them has become a hot topic. Herein, a magnetically separable Fe3O4@TiO2/g-C3N4 photocatalyst with a special heterojunction structure was fabricated, and its photocatalytic performance was assessed by degrading tetracycline (TC). Compared to Fe3O4@TiO2, the synthesized Fe3O4@TiO2/g-C3N4 exhibited superior TC degradation performance, which was primarily ascribed to the heterojunction formed between TiO2 and g-C3N4 and its ability to enhance the visible light absorption capacity and reduce the photoinduced electron/hole recombination rate. Moreover, a free radical capture experiment further confirmed that ·O2− and h+ are the predominant components in the TC degradation reaction. Under UV–Vis irradiation, the TC degradation rate escalated to as high as 98% within 120 min. Moreover, Fe3O4@TiO2/g-C3N4 was demonstrated to be easily recovered by magnetic separation without any notable loss even after five cycles, showing exceptional stability and reusability. These findings indicate that Fe3O4@TiO2/g-C3N4 is a promising photocatalyst for environmental remediation that may provide a sustainable approach to degrading antibiotic pollutants in wastewater.

Highly adsorptive removal of heavy metal, dye, and antibiotic pollutants using functionalized graphene nanosheets sono-electrochemically derived from graphitic waste

The development of highly adsorptive materials at low cost is critically important for efficient treatment of industrial wastewater. We herein report a one-step sonoelectrochemical strategy to synthesize functionalized graphene (FG) nanosheets as an effective adsorptive material using graphite waste from spent household batteries. Scanning/transmission electron and Raman microscopy studies reveal that the as-synthesized nanosheets are composed of few (2–6) graphene layers. Additionally, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses imply the presence of oxygen functional groups on the nanosheets (CO and -COOH, oxygen content of 4.29%), which are immensely beneficial for the electrostatic adsorption with heavy metals, dyes, and antibiotics in aqueous solutions. As expected, FG nanosheets exhibit potent capabilities of handling a wide range of pollutants, such as methylene blue, methyl orange, enrofloxacin, and Pb2+, with high adsorption performances (99.95% and 21.21 mg/g for Enrofloxacin, 98.93% and 119.3 mg/g for methylene blue, 95.82% and 25.67 mg/g for methyl orange, 95.56% and 86.10 mg/g for Pb2+). These findings therefore show a great promise for practical uses of the FG material as efficient adsorbents in eliminating metallic, organic, and antibiotic pollutants in water.

Conjugating HA bundles with ZIF-8 for catalytic degradation of tetracycline and antibacterial capacity

The overused of antibiotics had led to major environmental issues and drug-resistant bacteria, which inevitably harmed the environment and public health. In this work, in order to obtain environmentally friendly bi-functional materials to combat with residual antibiotics and bacterial contamination, ZIF-8, a typical Zn based zeolitic imidazolate framework (ZnZIF) with excellent chemical stability, was conjugated to hydroxyapatite nanowire bundles (HAnBs) by a simple in-situ synthesis. The obtained ZnZIFs@HAnBs was characterized by SEM, EDS, XPS, FT-IR, XRD and BET. The effects of catalysts, catalyst dosage, TC initial concentration, PMS concentration and pH on TC degradation were investigated. Notably, ZnZIFs@HAnBs (94.0 %) exhibited excellent degradation effect of tetracycline (TC) within 15 min, which was 1.7 and 5.2 times than that of ZIF-8 (55.9 %) and HAnBs (18.1 %) under optimal conditions, respectively. Moreover, after recycling 10 times, the degradation rate still more than 86.8 %. The degradation mechanism was confirmed by free radical quenching experiment coupling with electron paramagnetic resonance (EPR), and the 1O2 and O2•- were the major reactive oxygen species in TC degradation. Furthermore, it presented excellent antibacterial activity (95.0 %) against E. coli and S. aureus, which was attributed to the synergistic effect of sustained release of Zn2+ and phosphate in ZnZIF@HAnBs. In summary, an eco-friendly bi-functional materials of HA nanowire bundles could be synthesized by simple strategy, and it could be applied in the fields of environmental remediation, as well as in treatment of antibiotic and bacterial pollution.

MOF-on-MOF-derived Fe[sbnd]Zr bimetal oxides supported on hierarchically porous carbonized wood to promote photo-Fenton degradation of ciprofloxacin

MOF-on-MOF derivatives have served as promising heterogeneous Photo-Fenton (hetero-PF) catalysts, but its self-aggregation instability and limited photocatalytic activity inhibit the effective ciprofloxacin (CIP) removal. In this study, a novel hetero-PF catalyst, dual MOF-derived FeZr bimetal oxide embedded in a wood-converted porous carbon skeleton (ZrO2@Fe3O4/WPC), was successfully synthesized via a straightforward in-situ growth strategy combined with co-pyrolysis. The as-prepared hybrid photocatalysts, featuring a large surface area, effective porous structures, efficient light absorption and a narrow band gap demonstrated superior photo-Fenton activity, accomplishing approximately 99.1 % degradation of CIP within 120 min under neutral conditions. Furthermore, the ZrO2@Fe3O4/WPC hetero-PF system showed satisfactory performance in treating real water matrices. It can be inferred that the abundant heterojunctions, resulting from the synergistic effect of FeZr mixed oxide and the porous carbonized wood substrate, contributed to the rapid separation and migration of photogenerated electron-hole pairs. Meanwhile, the FeZr site in the graphitized carbon framework activates H2O2 to accelerate the generation of the OH and O2− radicals, leading to a heightened degradation efficiency of CIP. Besides, the photodegradation pathway of CIP is obtained by liquid chromatography-mass spectrometry (LC-MS). This study indicates that combining porous carbonized wood and heterometallic MOF derived materials provides a promising method for realizing high-efficiency photo-Fenton degradation of antibiotic water pollutions.

Unveiling antibiotic contamination in surface water: A study of the Huaihe River Basin's Huaibei Plain, a significant Chinese herbal medicine planting region

The abuse of antibiotics has caused the accumulation of antibiotic residues in environmental media, threatening the ecosystem and human health. Many studies on the distribution of aqueous antibiotics have been reported. However, the pollution status of antibiotics in the environment in Chinese herbal medicine planting areas is rarely comprehensively clarified, resulting in the lack of updated pollution data and conducive suggestions for ecological cultivation and sustainable development of Chinese herbal medicine. Thus, we comprehensively investigated the distribution, profiles, sources, and risks of the antibiotics in the surface water of an important tributary of the Huaihe River Basin, located in Bozhou City, a significant Chinese herbal medicine planting region. Solid-phase extraction coupled with an ultra-performance liquid chromatography-tandem mass spectrometer (SPE-UPLC-MS) was utilized to detect the antibiotics in the water. 27 kinds of antibiotics were identified with total concentrations ranging from 75.01 to 1737.99 ng·L−1, with doxycycline (DC) and doxycycline hydrochloride (DCH) possessed the highest concentration. And DC, DCH, oxilinic acid (OA), sulfamethoxazole (SMZ), clarithromycin (CLA), and roxithromycinum (ROX) were the main antibiotics detected in this basin. Correlation analysis and principal component analysis (PCA) indicated that animal husbandry was the primary source of antibiotics. Furthermore, the ecological risk assessment revealed that certain antibiotics could seriously threaten the survival of aquatic organisms, implying that local Chinese herbal medicines might be at similar growth risk. The drinking risk assessment showed that antibiotics in the water posed low risks for human, and children faced a greater drinking risk than adults. The study can help to facilitate the management of aqueous antibiotic pollution for the ecological cultivation and safe production of Chinese herbal medicine.

Efficient photodegradation of antibiotics by g-C3N4 and 3D flower-like Bi2WO6 perovskite structure: Insights into the preparation, evaluation, and potential mechanism

Antibiotics are emerging organic pollutants that have attracted huge attention owing to their abundant use and associated ecological threats. The aim of this study is to develop and use photocatalysts to degrade antibiotics, including tetracycline (TC), ciprofloxacin (CIP), and amoxicillin (AMOX). Therefore, a novel Z-scheme heterojunction composite of g-C3N4 (gCN) and 3D flower-like Bi2WO6 (BW) perovskite structure was designed and developed, namely Bi2WO6/g-C3N4 (BW/gCN), which can degrade low-concentration of antibiotics in aquatic environments under visible light. According to the Density Functional Theory (DFT) calculation and the characterization results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FITR), Scanning electron microscopy - energy spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), this heterojunction was formed in the recombination process. Furthermore, the results of 15 wt%-BW/gCN photocatalytic experiments showed that the photodegradation rates (Rp) of TC, CIP, and AMOX were 92.4%, 90.1% and 82.3%, respectively, with good stability in three-cycle photocatalytic experiments. Finally, the quenching experiment of free radicals showed that the holes (h+) and superoxide radicals (·O2−) play a more important role than the hydroxyl radicals (·OH) in photocatalysis. In addition, a possible antibiotic degradation pathway was hypothesized on the basis of High performance liquid chromatography (HPLC) analysis. In general, we have developed an effective catalyst for photocatalytic degradation of antibiotic pollutants and analyzed its photocatalytic degradation mechanism, which provides new ideas for follow-up research and expands its application in the field of antibiotic composite pollution prevention and control.

Alien emergent aquatic plants develop better ciprofloxacin tolerance and metabolic capacity than one native submerged species

Antibiotic pollution and biological invasion pose significant risks to freshwater biodiversity and ecosystem health. However, few studies have compared the ecological adaptability and ciprofloxacin (CIPR) degradation potential between alien and native macrophytes. We examined growth, physiological response, and CIPR accumulation, translocation and metabolic abilities of two alien plants (Eichhornia crassipes and Myriophyllum aquaticum) and one native submerged species (Vallisneria natans) exposed to CIPR at 0, 1 and 10 mg/L. We found that E. crassipes and M. aquaticum's growth were unaffected by CIPR while V. natans was significantly hindered under the 10 mg/L treatment. CIPR significantly decreased the maximal quantum yield of PSII, actual quantum yield of PSII and relative electron transfer rate in E. crassipes and V. natans but didn't impact these photosynthetic characteristics in M. aquaticum. All the plants can accumulate, translocate and metabolize CIPR. M. aquaticum and E. crassipes in the 10 mg/L treatment group showed greater CIPR accumulation potential than V. natans indicated by higher CIPR contents in their roots. The oxidative cleavage of the piperazine ring acts as a key pathway for these aquatic plants to metabolize CIPR and the metabolites mainly distributed in plant roots. M. aquaticum and E. crassipes showed a higher production of CIPR metabolites compared to V. natans, with M. aquaticum exhibiting the strongest CIPR metabolic ability, as indicated by the most extensive structural breakdown of CIPR and the largest number of potential metabolic pathways. Taken together, alien species outperformed the native species in ecological adaptability, CIPR accumulation and metabolic capacity. These findings may shed light on the successful invasion mechanisms of alien aquatic species under antibiotic pressure and highlight the potential ecological impacts of alien species, particularly M. aquaticum. Additionally, the interaction of antibiotic contamination and invasion might further challenge the native submerged macrophytes and pose greater risks to freshwater ecosystems.

Antibiotic exposure alters the honeybee gut microbiota and may interfere with the honeybee behavioral caste transition.

Behavioral division is essential for the sustainability and reproduction of honeybee populations. While accumulating evidence has documented that antibiotic exposure interferes with bee behavioral divisions, how the gut microbiome, host physiology, and genetic regulation are implicated in this process remains understudied. Here, by constructing single-cohort colonies, we validated that the gut microbiota varied in composition between age-matched nurse and forager bees. Perturbing the gut microbiota with a low dose of antibiotic retained the gut bacterial size, but the structure of the microbial community continuously diverged from the control group after antibiotic treatment. Fewer foragers were observed in the antibiotic groups in the field experiment. A combinatorial effect of decreased gut metabolic gene repertoires, reduced brain neurotransmitter titers, and downregulated brain immune genes could potentially be related to behavioral tasks transition delay. This work indicates that the disturbance to both the gut microbiome and host physiologies after antibiotic exposure may have implications on social behavior development, highlighting the need for further research focusing on antibiotic pollution threatening the honeybee population's health.

Indirect Impact of Eutrophication on Occurrence, Air-Water Exchange, and Vertical Sinking Fluxes of Antibiotics in a Subtropical River.

A significant challenge that warrants attention is the influence of eutrophication on the biogeochemical cycle of emerging contaminants (ECs) in aquatic environments. Antibiotics pollution in the eutrophic Pearl River in South China was examined to offer new insights into the effects of eutrophication on the occurrence, air-water exchange fluxes (Fair-water), and vertical sinking fluxes (Fsinking) of antibiotics. Antibiotics transferred to the atmosphere primarily through aerosolization controlled by phytoplankton biomass and significant spatiotemporal variations were observed in the Fair-water of individual antibiotics throughout all sites and seasons. The Fsinking of ∑AB14 (defined as a summary of 14 antibiotics) was 750.46 ± 283.19, 242.71 ± 122.87, and 346.74 ± 249.52 ng of m-2 d-1 in spring, summer, and winter seasons. Eutrophication indirectly led to an elevated pH, which reduced seasonal Fair-water of antibiotics, sediment aromaticity, and phytoplankton hydrophobicity, thereby decreasing antibiotic accumulation in sediments and phytoplankton. Negative correlations were further found between Fsinking and the water column daily loss of antibiotics with phytoplankton biomass. The novelty of this study is to provide new complementary knowledge for the regulation mechanisms of antibiotics by phytoplankton biological pump, offering novel perspectives and approaches to understanding the coupling between eutrophication and migration and fate of antibiotics in a subtropical eutrophic river.

Bronze TiO2-MXene heterostructures for dramatic enhancement of photocatalytic degradation of tetracycline under visible light

Although TiO2 nanomaterials have been widely used for the photocatalytic degradation of antibiotic pollutants in aqueous environments under ultraviolet (UV)-light irradiation, their photocatalytic performances are still unsatisfactory under visible light because of the large band gap. Herein, the bronze TiO2-MXene (TiO2(B)-MXene) heterostructures are successfully prepared and serve as photocatalysts to degrade the tetracycline (TC) pollutants under visible light for the first time. As a result, the heterostructure photocatalysts (20 mg) realize almost ∼ 92 % degradation efficiency of TC (20 mg L-1, 100 mL) in 40 min under the irradiation of Xe lamp (300 W), attributing to the synergistic effect of MXene nanosheets and TiO2(B) nano-flowers.

Synergistic photocatalytic removal of moxifloxacin from aqueous solutions using ZnO-Fe3O4-chitosan composites

The escalating contamination of water bodies with antibiotic residues is an urgent environmental and public health issue. This study aimed to fabricate an innovative photocatalytic composite (CMZ) by combining chitosan, magnetic iron oxide (Fe3O4), and zinc oxide (ZnO) for efficiently removing antibiotic moxifloxacin (MFX) water. Comprehensive characterization of the fabricated CMZ was performed using various techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), photoluminescence spectroscopy (PL) and nitrogen adsorption/desorption isotherm analysis. The synergistic incorporation of ZnO, Fe3O4, and chitosan in the CMZ composite altered the structural properties of ZnO and chitosan The band gap energy of CMZ was 2.58 eV, significantly boosting its photocatalytic effectiveness under visible light exposure. The CMZ composites exhibited a high efficiency in catalyzing MFX degradation in aqueous environments. The optimal conditions for MFX degradation were established, including a neutral pH level of 7, a 90 min exposure to irradiation, and employing 0.1 g of the CMZ catalyst. The degradation process obeyed closely to the first-order kinetic model. The CMZ material showed consistently high performance in degrading MFX across four consecutive reuse cycles, emphasizing its practical applicability for mitigating antibiotic pollution.

Sustainable synthesis of praseodymium tungstate: An electrochemical probe for detection of Ronidazole

Profligate consumption of antibiotics in animal and livestock husbandry indulged in antibiotic pollution. This collapses the natural balance of the ecosystem and results in various environmental health crises. Herein, we have developed an ultra-sensitive praseodymium tungstate (PWO) based electrochemical sensor to detect one such serious antibiotic, Ronidazole (RD). A facile synthesis strategy was applied to prepare PWO nanomaterial and their structural, functional, and elemental details were thoroughly examined with a wide range of spectroscopic measurements. The electrochemical properties were determined by performing impedance and voltammetry experiments. The high catalytic efficiency of the designed sensor was achieved by optimizing its performance under different parameters. Based on the outcomes, the designed PWO-based sensor offered an extremely low level of detection (0.3 nM) and exhibited a wide range of linearity (0.001 µM to 20.4 µM), high sensitivity (7.72 µA µM−1 cm−2), and good selectivity. Further, the performance of the electrochemical sensor was validated with good repeatability, reproducibility, and stability results. The practical applicability of the sensor was investigated by monitoring the RD in aquatic, biological, and pharmaceutical samples. The obtained results affirmed that the PWO sensor is an efficient platform for the real-time monitoring of RD.