Antibiotic Wastewater Research Articles

MXene/TiO2 NAs on CC flexible electrode for electrocatalytic tigecycline degradation: Performance, Mechanistic insights, and toxicological assessment

In this study, a composite electrode (MXene/TiO2 NAs@CC) based on TiO2 nanotube arrays (NAs) and two-dimensional MXene-coated carbon cloth (CC) was prepared. The electrode greatly improved the catalytic activity by capturing protons through the abundant active sites of TiO2 nanotube arrays and promoting proton reduction with the high conductivity of MXene. Moreover, the composite electrode possessed the largest specific surface area (9.1660 m2·g−1) according to the results of the BET test. Under optimal conditions, the composite electrode degraded tigecycline (TGC) up to 86.66 % in 20 min. Furthermore, the electrocatalytic performance was not affected after 10 cycling experiments and 60 days of exposure to air, indicating its excellent stability. In addition, the cathodic co-catalytic reaction mechanism involving anode ·OH, HClO, and cathode H* was proposed. The degradation pathways of TGC and the toxicity of possible intermediates were also analyzed. Finally, a two-stage continuous wastewater reactor with high efficiency and low consumption (90.46 % removal rate, 0.061 kWh/m3) was designed. This study provides a new idea for designing an electrocatalytic reactor with high efficiency, stability, and low consumption, enriching the field of electrocatalytic treatment strategies for antibiotic wastewater. It is of great significance for the protection of the water environment and human health.

Highly efficient photocatalytic degradation of tetracycline antibiotic enabled by TiO2 nanodispersion

The growing pollution of antibiotics poses a significant threat to the ecological environment and human health. Photocatalysis is a promising solution for eliminating tetracycline (TC), but developing efficient photocatalysts remains a critical and challenging task. Herein, TiO2 nanodispersion is first used for the removal of TC in water. The as-prepared TiO2 nanodispersion has a uniform size of 10 nm and a large specific surface area of 198.9 m2/g, exhibiting notable adsorption capacity, exceptional photocatalytic performance, and considerable stability. Under UV light, TiO2 nanodispersion achieved 100 % degradation of TC within 60 min, using less than 1/5 of the catalyst dosage typically applied in most studies, and exhibited the highest catalytic activity, reaching 500 mgTC∙gcatalyst-1h-1. Additionally, the photocatalytic rate constant of TiO2 nanodispersion was 2.74 times higher than commercial P25. After five photocatalytic cycles, the catalyst maintained a high degradation efficiency of 94 %. Even under visible light, the degradation efficiency of TC by TiO2 nanodispersion was approximately 90 % within 20 min, which was notably higher than that of P25 (63 %). Moreover, the as-prepared TiO2 nanodispersion demonstrated outstanding photocatalytic degradation ability for other typical antibiotics (chlortetracycline, oxytetracycline, and ciprofloxacin), demonstrating its potential as an efficient photocatalyst for the treatment of antibiotic wastewater.

Novel insights into revealing the intrinsic degradation mechanism of ciprofloxacin by Chlorella sorokiniana: Removal efficiency, pathways and metabolism

Microalgae-mediated biodegradation of antibiotics has attracted increasing interest. However, the exact degradation mechanism behind it remains elusive, which is crucial for improving its efficiency and large-scale implementation. Therefore, this study aims to thoroughly investigate how Chlorella sorokiniana (C.sorokiniana) degrades ciprofloxacin (CIP) from the molecular level to elucidate its complicated degradation mechanism. Results show that C.sorokiniana exhibited an impressive removal rate of 38.05–74.29 % for CIP, the synergistic effect of biosorption and biodegradation was the main removal mechanism of CIP. The content of EPS increased by 11.84–103.31 %, acting as a carrier to increase the bioavailability of CIP. Enzyme activity analysis identified POD, CYP450, and GST as the major catalytic enzymes responsible for the biotransformation process of CIP with increases of 6–41.2 %, 18.78–102.1 % and 3.53–58.15 %, respectively. Molecular docking further revealed that the binding affinity of 146.24 μM, 27.71 μM and 16.33 μM was observed for POD,CYP450, and GST, respectively, indicating the high metabolic efficiency of CIP by CYP450. Finally, DFT calculations elucidated the enzyme-mediated biodegradation pathway of CIP, including hydroxylation, decarboxylation, and ring opening. These findings are expected to further fill the knowledge gap on the catalysis mechanism of CIP degradation by enzymes and improve the practical application of microalgae to antibiotic wastewater.

MIL-125-PDI/ZnIn2S4 Inorganic-Organic S-Scheme Heterojunction With Hierarchical Hollow Nanodisc Structure for Efficient Hydrogen Evolution from Antibiotic Wastewater Remediation.

Efficient photocatalytic production of H2 from wastewater is expected to address environmental pollution and energy crises effectively. However, the rapid recombination of photoinduced carriers results in low photoconversion efficiency. At present, inorganic-organic S-scheme heterojunction have become a prominent and promising technology. In this study, an organic ligand modified MIL-125-PDI/ZnIn2S4 (ZIS) inorganic-organic S-scheme heterojunction catalyst is designed. ZIS nanosheets are grown on the disc-shaped MIL-125-PDI surface to form a distinctive hollow nanodiscs with hierarchical structure, giving the material an abundance of surface active sites, an optimized electronic structure, and a spatially separated redox surface. Consequently, the optimal 100MIL-125-PDI250/ZIS exhibited high photocatalytic HER of 508.99 µmol g-1 h-1 in Tetracycline hydrochloride (TC-HCl) solution. Meanwhile, the catalyst achieved complete TC-HCl removal and mineralization rate of 66.62% in 4h. Experimental and theoretical calculations corroborate that the staggered band alignment and work function difference between MIL-125-PDI and ZIS induce the formation of a built-in electric field, thus regulating the charge transfer routes and consequently enhancing charge separation efficiency. The possible photocatalytic mechanism is analyzed using liquid chromatography-mass spectrometry (LC-MS), and the toxicities of the degradation products are also evaluated. This work presents a green dual-function strategy for H2 production and antibiotic wastewater recycling.

Zirconium-doped lead dioxide anodes prepared by sol-gel method for ampicillin removal from simulated pharmaceutical polluted wastewater.

New anodes consisting of zirconium-doped PbO2 coating, growth on titanium dioxide interlayer, were deposited on titanium substrates using spin coating method and have been tested for the removal of ampicillin, a β-lactam antibiotic, from water. Morphological, structural, and electrochemical properties of the prepared coatings were characterized by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), and electrochemical impendence spectroscopy (EIS). Results showed that the incorporation of zirconium dopant had a noticeable modification in the morphology of anodes. An increase in the surface roughness and the specific active area were observed with Ti/TiO2/PbO2- 10% Zr electrode compared to other anodes. The electrochemical measurements indicated that the anode doped with 10% Zr showed a more protective coating performance than the undoped and 20% Zr-doped PbO2 electrodes. The experiments on ampicillin degradation revealed that doped lead dioxide anodes have excellent electrocatalytic activity. The major byproduct generated during anodic oxidation treatment has been identified as ampicilloic acid by liquid chromatography-mass spectroscopy (LC-MS) analysis. Results demonstrated that Ti/TiO2/PbO2- 10% Zr anode presents the best removal rate of ampicillin with a minimum intermediate amount, which leads to conclude that 10% is the optimum percentage of zirconium dopant for antibiotic wastewater treatment.

Advanced Graphene-Based Technologies for Antibiotic Removal from Wastewater: A Review (2016–2024)

The increasing presence of antibiotics in wastewater poses significant environmental risks, including the promotion of antibiotic resistance and harm to aquatic ecosystems. This study reviews advancements in graphene-based technologies for removing antibiotics from wastewater between 2020 and 2024. Graphene-based platforms, such as graphene oxide (GO), reduced graphene oxide (rGO), and graphene composites, have shown great promise in this field because of their exceptional adsorption capacities and rapid photocatalytic degradation capabilities. Functionalized graphene materials and graphene integrated with other substances, such as metal oxides and polymers, have enhanced performance in terms of antibiotic removal through mechanisms such as adsorption and photocatalysis. These technologies have been evaluated under various conditions, such as pH and temperature, demonstrating their practical applicability. Despite challenges related to scalability, cost-effectiveness, and environmental impact, the advancements in graphene-based technologies during this period highlight their significant potential for effective antibiotic removal, paving the way for safer and more sustainable environmental management practices.

Application of electro-activated persulfate oxidation enhanced with an ultraviolet process in a multi-stage flow-through filtration system for antibiotics abatement

The treatment of antibiotic wastewater from various water matrices remains challenging because of some complex pollutants in nature. Single treatment methods are often inadequate for eliminating these contaminants. The integrated technology is brilliantly effective over an individual process alone. The electro-activated persulfate oxidation enhanced with an ultraviolet process (EO/PS/UV) was established as a novel technology in antibiotic wastewater treatment. It exhibited to be highly effective with much more efficiency in degrading amoxicillin (AMX) (97.10 %) than the two couple and individual processes in a multi-stage flow-through reactor. The Box-Behnken design’s quadratic model using the response surface methodology (RSM) revealed a reasonable prediction with a suggestive correlation of R2 = 0.9986. This study shows that the AMX degradation mechanism in the EO/PS/UV process involves coordinating of SO4·-, and OH, with OH playing a more significant role. It could effectively treat the tetracycline and sulfamethoxazole within 40 min in both simulated wastewater and secondary effluent, except for tetracycline, which took only 30 min in simulated wastewater. However, AMX did not undergo sufficient removal within 100 min and required a higher EE/O compared to other pollutants. Lastly, the integrated technology has proven to be an efficient and energy-saving method for eliminating antibiotics with promising standpoints for various wastewater treatments.

Customizable Three-Dimensional Printed Zerovalent Iron: An Efficient and Reusable Fenton-like Reagent for Florfenicol Degradation.

Zerovalent iron (Fe0)-based Fenton-like technology has great potential for treating recalcitrant organic pollutants (ROPs) in wastewater. However, rapidly and precisely manufacturing Fe0-based materials with the desired geometries is challenging. Herein, novel three-dimensional printed Fe0 (3DP-Fe0) and bimetallic 3DP-Ni/Fe0 were customized by 3D printing for efficient Fenton-like degradation of florfenicol (FLO), a typical antibiotic in wastewater. 3DP-Ni/Fe0 with hydrogen peroxide (H2O2) exhibited superior reactivity toward FLO than 3DP-Fe0, generating hydroxyl radicals (·OH) and atomic hydrogen to achieve >90% dehalogenation and >70% total organic carbon removal within 10 min. The resulting degradation intermediates possessed lower antibacterial activity than FLO and did not cause resistance gene proliferation in activated sludge. The Fenton-like activity of 3DP-Ni/Fe0 was similar across different shapes but increased with increasing porosity and size. Compared with powdered Ni/Fe0, 3DP-Ni/Fe0 exhibited faster electron transfer during Fe(II)/Fe(III) cycling, which increased the utilization efficiency of dissolved Fe2+ and H2O2 for ·OH production. Moreover, 3DP-Ni/Fe0 could be reused >150 times, 5-fold more than powdered Ni/Fe0, owing to its lower metal ion release and Fe0 depletion. 3DP-Ni/Fe0 with H2O2 can also efficiently remove chemical oxygen demand from real wastewater and other ROPs (e.g., acetaminophen, carbamazepine, thiamphenicol, and tetrabromobisphenol A).

Mechanistic and DFT studies on the degradation of metronidazole by cerium oxide-loaded iron-cobalt layered double hydroxide-activated calcium sulfite

In this study, Co3Fe-LDHs loaded with CeO2 were synthesized via a hydrothermal method, and the synthesized Co3Fe-LDHs@CeO2 exhibited excellent surface properties and structural stability. Moreover, Co3Fe-LDHs@CeO2 was first applied to activate CaSO3 for metronidazole (MNZ) degradation. The effects of the catalyst preparation ratio, initial pH, and coexisting substances in the system on MNZ degradation were investigated. At an initial pH of 7.0, when 0.2 g/L Co3Fe-LDHs@CeO2 and 2 mM CaSO3 were combined, 99 % of the MNZ at a concentration of 20 mg/L was eliminated in 60 min. The experimental results revealed the rapid activation of CaSO3 on the catalyst surface, where Ce plays a key role in the redox cycle between Co and Fe atoms. The loading of CeO2 enhanced the catalytic performance of Co3Fe-LDHs, as confirmed by density functional theory (DFT) calculations. The loading of Ce promoted the chemisorption of CaSO3 on the surface of Co3Fe-LDHs@CeO2, leading to the transfer of 1.48 electrons from sulfite to Co3Fe-LDHs@CeO2. These findings were consistent with the results of the electrochemical tests. SO4•- and •OH were identified as the primary active substances through electron paramagnetic resonance (EPR) and chemical probe experiments, accounting for 60.73 % and 32.81 %, respectively. By combining LC–MS and DFT calculations, three potential degradation pathways of MNZ were identified, with the intermediates found to be either nontoxic or have low toxicity. Even after being recycled five times, MNZ still showed 88 % degradation, demonstrating its exceptional reusability. Co3Fe-LDHs@CeO2 shows great potential for practical use in treating antibiotic wastewater due to its outstanding catalytic properties, anti-interference ability, reusability, and stability.

Electrochemistry enhanced multi-stage biological contact oxidation treating sulfamethoxazole wastewater: Performance, degradation pathway and microbial community

Clean and economical techniques are in urgent need for improving antibiotics removal from wastewater. In this study, a multi-stage bio-contact oxidation reactor (BCOR) was constructed and further enhanced by electrochemistry to treat sulfamethoxazole (SMX) wastewater. The stimulatory effects of the electrochemistry were investigated together with the succession of microbial communities as well as the possible conversion pathways of SMX. The results showed that the SMX and chemical oxygen demand removal rates reached up to 92.96 ± 0.62 % and 91.42 ± 0.82 % at electric current density of 2.0 mA/cm2. Electrochemistry enhancement induced bone cleavage and oxidation transformation pathways of SMX while reduced the toxicity of degrading intermediates. Moreover, electrochemistry enhancement stimulated the growth of Klebsiella and Rhodobacter as well as the fermentation, chemoheterotrophy and aerobic_chemoheterotrophy functions which further promoted the SMX removal. This study revealed the biochemical removal mechanisms of SMX degradation and manifested the feasibility of combing electrochemistry with BCOR to treat antibiotics wastewater with low energy consumption.

Screening potential biomarkers for acute respiratory infectious diseases from antipyretics, antiviral, and antibiotics in wastewater

Since the onset of COVID-19, respiratory diseases have emerged as a focal concern within the field of public health. This study aims to reveal the prevalence of acute respiratory infectious diseases by screening antipyretic, antiviral, and antibiotic biomarkers through wastewater analysis. Samples were collected over a seven-day period each year in 2022, 2023, and 2024 from a northern city in China, assessing the concentrations of two antipyretics (paracetamol and ibuprofen), one antiviral drug (oseltamivir), eleven antibiotics, and three pathogens (influenza A, influenza B, and Mycoplasma pneumoniae). The usage of most antipyretics and antibiotics was higher in 2023 and 2024, primarily due to the outbreak of COVID-19 in 2023 and the prevalence of influenza A, influenza B, and Mycoplasma pneumoniae in 2024. The prevalence assessed using antipyretics (2.68 %) and pathogens (2.70 %) demonstrated a high degree of consistency, whereas the prevalence estimated using antibiotics and antiviral drugs was only 0.53 % and 0.36 %, respectively. Antibiotics are generally used to treat a broad spectrum of bacterial infections rather than targeting a specific pathogen, so their presence in wastewater may not directly reflect the prevalence of a particular disease. In contrast, antipyretics and specific pathogens exhibit a stronger correlation, suggesting that they may serve as more reliable biomarkers than antiviral and antibiotic drugs. The research findings offer alternative biomarkers, such as antipyretics, aside from pathogens, for the assessment of acute respiratory infectious diseases.

Multicolor fluorescence strategy for rapid and simultaneous detection of antibiotics in wastewaters and the entire process detection mechanisms

Fluorescence nano-sensors have recently emerged as a cost-effective, convenient, and time-saving tool for high-throughput detection of antibiotics in wastewater. However, their application is primarily limited to tetracycline and penicillin due to a lack of understanding of key influencing factors. Herein, we propose a convenient strategy to expand their application range by increasing the colors of fluorescence nano-sensors. The newly three-colored nano-sensors were prepared to detect erythromycin and metronidazole, which has rarely been reported before. For in-situ detection, a smartphone app-based detection method was developed, and the detection method was optimized to obtain the widest detection limit. The fluorescence nano-sensors demonstrated satisfactory recovery rates with promising accuracy in various types of wastewaters. Moreover, a mechanism investigation comprising experimental analysis and theoretical simulation was developed to elucidate their detection mechanisms and provide ideas for improving their performance. Consequently, several improvements were proposed further to enhance the analysis selectivity, sensitivity, and accuracy. This work presents a new perspective on broadening the application of fluorescence nano-sensors and provides a novel route to analyze the detection mechanism, enabling rapid, high-throughput and in-situ detection of antibiotics.

Synergistic effects enabled efficient photocatalytic removal of ofloxacin antibiotic in wastewater by layered double hydroxides loaded lignin-derived carbon fibers

The environmental problems caused by the abuse of antibiotics are raising serious attention, and the removal of antibiotics in wastewater is meaningful yet challenging. In this work, lignin-derived carbon fibers loaded layered double hydroxides (LDH@LCF) has been prepared for the removal of ofloxacin (OFX) from wastewater via photocatalysis, which exhibit a high degradation efficiency of 96 % under visible light and maintained 90 % after five reuses. The effects of Zn2+/Fe3+ in the samples and other parameters affecting the photocatalytic efficiency of OFX have been systematically investigated. Results demonstrated that the enhanced photocatalytic efficiency is derived from the synergistic effect of the Zn2+ and Fe3+ in the LDH with a reduced band gap of the catalyst, higher number of oxygen and metal unsaturated coordination sites, and rapid removal of photogenerated electrons. The working mechanism and degradation pathways for OFX by LDH@LCF are also elucidated in detail.

Construction of a multiple reactive species-mediated Co9S8/NBC-PMS Fenton-like system for tetracycline degradation with broadened adaptability to water background

A Fenton-like system based on peroxymonosulfate (PMS) oxidant has high potential for antibiotic degradation, However, various complex water background factors, including pH, coexisting ions, and dissolved organic matter, can adversely affect degradation efficiency. This work constructed a PMS oxidative Fenton-like system activated by cobalt polysulfide/N-doped biochar composite (Co9S8/NBC) for the degradation of tetracycline (TC) and achieving approximately 99 % removal of TC. Furthermore, the removal efficiency was maintained above 90 % across a broad pH range (3−11), in the presence of various coexisting anions (Cl−, NO3− and CO32−), even at high concentrations of humic acid. The characterization of Co9S8/NBC through various techniques confirmed that Co9S8 nanoparticles were uniformly loaded within the porous NBC structure. Electron paramagnetic resonance and reactive oxygen species (ROSs) quenching experiment revealed that the effectiveness of TC degradation in the Co9S8/NBC/NBC-PMS system arises from the cooperation of radical and non-radical species rather than the single mechanism. Moreover, the analysis of the contribution ratios of ROSs to TC degradation indicates that the contribution of non-free radicals exceeds that of free radicals, and it is capable of adapting to changes in pH. The characterization of the post-reaction catalyst suggested that Co9S8 and NBC synergistically participated in the activation of PMS. Moreover, the practical examination proved that the disabled Co9S8/NBC catalyst can recover the catalytic activity via a reheat treatment, the leaching concentration of Co ions was lower than the emission limit of China. The river water and lake water as the matrix water have little negative impact on the degradation of TC. The Co9S8/NBC-PMS system is expected to provide a practical pathway for the treatment of antibiotic wastewater.

Cerium-regulated Mg3FeO4@biochar activated persulfate to enhance degradation of aqueous tetracycline: The dominant role of cerium

The role of cerium (Ce) in Ce-regulated Mg3FeO4@biochar (CMF@BC) and the mechanism by which CMF@BC activates persulfate (PS) remain unclear. In this work, a novel CMF@BC was synthesized through the simple impregnation–pyrolysis process and utilized as a PS activator for the removal of aqueous tetracycline (TC). Under the optimal degradation conditions, the removal efficiency and mineralization rate of TC reached 92.7 % and 84.2 % within 60 min, respectively, the corresponding rate constant was 0.0487 min−1. The CMF@BC catalyst exhibited extremely high stability and excellent reusability after five cycles. The characterization results identified Fe2+ and oxygen vacancies as major catalytic sites. The Ce dopant inhibited the aggregation of metal ions of Mg3FeO4 during the high-temperature pyrolysis process and the Ce3+/Ce4+ redox cycle promoted Fe2+ regeneration, thus improving the catalyst performance. The degradation process was dominated by non-free radical (1O2) pathways. The possible TC-removal pathway was inferred from liquid chromatography–mass spectrometry results and density functional theory calculations. The toxicity of the degradation products was also evaluated. The CMF@BC catalyst displayed excellent catalytic performance and recyclability, wide pH adaptability, and a low ion-leaching rate, confirming its broad application prospects as a PS activator in antibiotic wastewater treatment.

Tree-like 3D GNP-rPN composite structure for solar-thermal evaporation and photocatalytic degradation of antibiotic wastewater

To realize high-yield and long-term purification of wastewater containing antibiotic ciprofloxacin hydrochloride (CIP) and seawater, a tree-like 3D GNP-rPN solar-driven water evaporation and photocatalysis evaporator is developed by preparing and assembling GO/NPDI/PVA (GNP) hydrogel (canopy) and rGO/PU/NPDI (rPN) foam (trunk). The “tree-like” evaporation and photocatalysis evaporator design in this work has the following three characteristics: First of all, graphene oxide (GO) and reduced graphene oxide (rGO) sheets broaden the light absorption range of the photocatalyst perylene imide nanowires (NPDI), which facilitates absorption of more sunlight; secondly, GO and rGO adsorb pollutants in water and provide them to NPDI for catalytic degradation under sunlight irradiation because of their huge specific surface area; thirdly, the excellent photothermal conversion ability of GO and rGO converts solar energy into heat energy, thus facilitating the catalytic degradation of CIP by NPDI. Thanks to the reduced enthalpy of water evaporation by GNP hydrogel, the sufficient top-down water supply, the superior photocatalytic performance of NPDI nanowires, and the efficient solar light absorption and solar-thermal energy conversion of the GO sheets and NPDI nanowires, the resultant GNP-rPN evaporation and photocatalysis system achieves an average water evaporation rate of 2.84 kg m−2 h−1 and a CIP degradation efficiency of 74.04 % within 1 h under 1-sun irradiation. The GNP-rPN system exhibits an optimal degradation efficiency of 74.04 % for a CIP solution with an initial concentration of 10 mg/L within 1 h of irradiation, reaching a degradation efficiency of 96.37 % after 4 h, demonstrating its effectiveness in purifying antibiotic-laden wastewater.

Effect of L-arginine and KMnO4 amendment on sulfonamide antibiotics wastewater treatment in an adsorption-biological coupling reactor: Insights from performance and functional genes analysis

The overuse of sulfonamide antibiotics (SAs) has placed considerable treatment pressure on wastewater treatment plants. The adsorption-biological coupling reactor we developed have been demonstrated to be effective in the treatment of SAs wastewater. However, the effect of filler modification on reactor performance and the degradation mechanisms of SAs remains inadequately understood. Herein, the amendment of filler with L-arginine and KMnO4 were investigated. The overall removal efficiency of COD, TP, NH3-N, sulfadiazine (SD), and sulfamethoxazole (SMX) in the reactor with L-arginine-modified coke (A-Coke) as filler were (79.29±15.29)%, (84.81±4.13)%, (92.67±11.25)%, (93.45±4.74)% and (93.60±4.13)%, while in the reactor with KMnO4-modified coke (K-Coke) as filler, the overall removal efficiency of COD, TP, NH3-N, SD and SMX were (90.60±6.68)%, (96.26±2.52)%, (95.14±5.29)%, (92.63±5.78)% and (93.65±6.48)%, respectively. The dominant bacteria in the reactor with A-Coke as filler were Azohydromonas, Propionibacterium, Bdellovibrio, and Sphingomonas, and those in the reactor with K-Coke as filler were Azohydromonas, Lysobacter, Plasticicumulans, and Cupriavidus. The compounds 4-hydroxy-2-aminopyrimidine, 4-hydroxy-2-hydroxy-aminopyrimidine, n-acetamide, 4-benzoquinone, 1,2, 4-trihydroxybenzene, 3-amino-5-methylisoxazole, and TP163 were detected as metabolites of SAs in the reactor filled with A-Coke. In contrast, 4-hydroxy-2-hydroxy-aminopyrimidine, 3-amino-5-methyl isoxazole, and TP163 as metabolites of SAs were detected in the effluent water of the reactor with K-Coke as filler. The results demonstrate that the amendment of L-arginine and KMnO4 could increase the performance of the adsorption-biological coupling reactor, which has potential application prospects in the treatment of SAs wastewater.

Unraveling the mechanism and the key role of amorphous structure C-O-Fe in tetracycline degradation by activation of persulfate in lotus leaf-based red mud-modified biochar

In the present study, red mud modified lotus leaf biochar was synthesized using a low-cost and concise method. The experimental results showed that when RM-HBC=0.4 g/L, PDS=4 mM, pH=5.0, the RM-HBC-PDS system exhibited the best degradation effect on TC, with the highest removal rate of 98.61 %, the highest degradation kinetics of 0.0229 min−1. Advanced characterization and density functional theory have demonstrated that the emergence of the C-O-Fe structure led to the redistribution of the surface charge of RM-HBC. This charge redistribution caused the electrons on the surface of RM-HBC to transfer from C to Fe through the C-O-Fe structure, forming an electron-rich center centered on Fe. The C-O-Fe structure facilitated the transformation of the Fe valence state within the RM-HBC while transmitting electrons, thus maintaining the regeneration of Fe(II). This further promoted the adsorption and activation ability of RM-HBC for PDS, thereby improving the degradation effect of TC in the system. XRD detection showed that the Fe3O4 crystal strength in RM-HBC after the reaction was significantly enhanced. This was due to the C-O-Fe present on the surface of RM-HBC in the process of degradation of TC, which accelerated sustained electron transfer at C-O-Fe, leading to structural fracture, recombination, and ultimately the formation of Fe3O4 crystals. Intermediate detection and toxicity prediction showed that the toxicity of TC was significantly reduced. All the above results confirmed that this study not only achieved the efficient treatment of antibiotic wastewater but also realized the rational utilization of lotus leaf and red mud resources.

Visible-light-response Fe-doped BiOCl microspheres with efficient photocatalysis-Fenton degradation of antibiotics

The combination of photocatalysis and Fenton reaction has been considered as a promising technology for the removal of antibiotics from wastewater. In this study, the Fe-doped BiOCl was synthesized by solvothermal method for photocatalysis-Fenton degradation of levofloxacin (LEV). Fe/BiOCl exhibited a flower-like microsphere structure with the lattice doping of Fe3+ in BiOCl. Under the synergistic of visible light irradiation and H2O2, the excellent degradation performance of Fe/BiOCl towards LEV was achieved (97.8 %) after 100-min reaction at Fe-doping content of 5 % and H2O2 addition of 3 mM. The Fe deposition extended the light absorption range and reduced the recombination of photogenerated carriers. The photogenerated electrons could accelerate the cycling of Fe2+/Fe3+, and improve the utilization efficiency of H2O2. The hydroxyl radical (OH), superoxide radical (O2−) and holes (h+) played crucial roles during the photocatalysis-Fenton degradation of LEV. The present study provided valuable insights into the development of photocatalysis-Fenton synergy system for the effective decontamination of antibiotic wastewater.

UV-Based Degradation of Fluoroquinolone Antibiotic in Wastewater: Effects of Process Parameters, Identification of Degradation Products and Evaluation of Residual Toxicity

UV-Based Degradation of Fluoroquinolone Antibiotic in Wastewater: Effects of Process Parameters, Identification of Degradation Products and Evaluation of Residual Toxicity