Antibiotic-containing Wastewater Treatment Research Articles

Efficient degradation of sulfonamides by introducing sulfur to magnetic Prussian blue analog in photo-assisted persulfate oxidation system

The peroxynitrite photocatalytic degradation system was considered a green, convenient, and efficient water treatment process, but not satisfying against some antibiotics, e.g. sulfonamides (SAs). To improve the photocatalytic degradation efficiency of SAs, sulfur was introduced to a magnetic Fe-MOF (Fe-metal organic framework) Prussian blue analog to achieve a heteroatomic material CuFeO@S, which was applied in heterogeneous visible light photo-assisted catalytic process with persulfate (PS) as an oxidant. The characterization results of CuFeO@S by XRD and XPS confirmed the presence of Fe3O4 (for magnetic separation), Cu+ (for activation of PS) and S2− (for narrowing the energy band and prolonging the lifetime of photo-generated electronics). Through systematic optimization of reaction conditions in CuFeO@S + PS + hv system, efficient degradation of four tested SAs was achieved in 30 min (removal rate of 97–100% for the tested 4 SAs). Moreover, the material could be magnetically recycled and reused for over 7 cycles with a removal rate of >90% for sulfamerazine. Furthermore, the removal rate of sulfamerazine in pond water reached 99% at a mineralization rate of about 34% (decrease in total organic matter), demonstrating its potential in the treatment of antibiotic-containing wastewater.

Using UV/peracetic acid as pretreatment for subsequent bio-treatment of antibiotic-containing wastewater treatment: Mitigating microbial inhibition and antibiotic resistance genes proliferation

UV/peracetic acid (PAA) treatment presents a promising approach for antibiotic removal, but its effects on microbial community and proliferation of antibiotic resistance genes (ARGs) during the subsequent bio-treatment remain unclear. Thus, we evaluated the effects of the UV/PAA on tetracycline (TTC) degradation, followed by introduction of the treated wastewater into the bio-treatment system to monitor changes in ARG expression and biodegradability. Results demonstrated effective TTC elimination by the UV/PAA system, with carbon-centered radicals playing a significant role. Crucially, the UV/PAA system not only eliminated antibacterial activity but also inhibited potential ARG host growth, thereby minimizing the emergence and dissemination of ARGs during subsequent bio-treatment. Additionally, the UV/PAA system efficiently removed multi-antibiotic resistant bacteria and ARGs from the bio-treatment effluent, preventing ARGs from being released into the environment. Hence, we propose a multi-barrier strategy for treating antibiotic-containing wastewater, integrating UV/PAA pre-treatment and post-disinfection with bio-treatment. The inhibition of ARGs transmission by the integrated system was verified through actual soil testing, confirming its effectiveness in preventing ARGs dissemination in the surrounding natural ecosystem. Overall, the UV/PAA treatment system offers a promising solution for tackling ARGs challenges by controlling ARGs proliferation at the source and minimizing their release at the end of the treatment process.

Degradation of sulfamethazine by microbial electrolysis cell with nickel-cobalt co-modified biocathode.

In this study, nickel-cobalt co-modified stainless steel mesh (Ni-Co@SSM) was prepared and used as the biocathode in microbial electrolysis cell (MEC) for sulfamethazine (SMT) degradation. The optimal electrochemical performance of the Ni-Co@SSM was obtained at the electrodeposition time of 600 s, electrodeposition current density of 20 mA cm-2, and nickel-cobalt molar ratio of 1:2. The removal of SMT in MEC with the Ni-Co@SSM biocathode (MEC-Ni-Co@SSM) was 82%, which increased by 30% compared with the conventional anaerobic reactor. Thirteen intermediates were identified and the potential degradation pathways of SMT were proposed. Proteobacteria, Firmicutes, Patescibacteria, Chloroflexi, Bacteroidetes, and Euryarchaeota are the dominant bacteria at the phylum level in the MEC-Ni-Co@SSM, which are responsible for SMT metabolism. Due to the electrical stimulation, there was an increase in the abundance of the metabolic function and the genetic information processing. This work provides valuable insight into utilizing MECs for effective treatment of antibiotic-containing wastewater.

Electro-induced activation of persulfate over N-doped porous carbon decorated with Fe/Ni bimetals for organic pollutants enhanced degradation: Synergism of electro-activation and catalytic activation

The booming demand for modern medicine has led to the widespread occurrence of antibiotics in aquatic environments. The co-activation of persulfate (PS) by electrochemical and catalytic processes has now drawn increasing interests for the treatment of refractory contaminants in water. Herein, N-doped porous carbon decorated with Fe/Ni bimetallic composite catalyst (FeNi-NC) was prepared with Fe-doped Ni-MOFs as a precursor. The composite catalyst was evaluated for it performance to catalyze PS in the presence of an electric field for the destruction of tetracycline (TC). Thanks to the synergistic effect between the electrochemical and Fe1Ni5-NC-600 catalytic processes to activate PS, the E-Fe1Ni5-NC-600 system exhibited a satisfactory performance for TC degradation, attaining a 91.94 % removal within 90 min. Electric field accelerated the redox cycles of Fe0/Fe2+/Fe3+ and Ni0/Ni2+/Ni3+ to realize the sustainable catalytic activation of PS to form reactive species (OH, SO4−, and 1O2) for enhanced TC degradation. Competition kinetics studies suggested OH was the dominant reactive species, and electron-transfer process also contributed to TC removal. Moreover, the E-Fe1Ni5-NC-600/PS system exhibited a low energy consumption (0.34 kWh/m3-log), wide effectiveness in the elimination of on different organic pollutants, and good applicability for real water treatment. This study provided new insights into the application of PS-based advanced oxidation process for the high-performance treatment of antibiotic-containing wastewater.

Degradation of tetracycline using persulfate activated by Mn, Ce co-doped g-C3N4 composites under visible light

The construction of efficient composite photocatalysts is significant for degrading antibiotic contaminants. Herein, a novel MnCe bimetallic-modified g-C3N4-based photocatalyst was synthesized using an impregnation calcination method and applied in persulfate (PS) activation under visible light (ViS). Characterization indicated that the doping of Mn and Ce bimetals promoted electron transfer and separation on the g-C3N4 surface. It broadened the visible light absorption range. Owing to the synergistic effect of visible light and PS, 1 wt% Mn-Ce/g-C3N4 had the highest removal rate of tetracycline (TC), reaching 89.1 % within 120 min of the reaction, and its kinetic constant was 3.2 times that of pure g-C3N4. Through quenching experiments, superoxide radicals (O2·−) and sulfate radicals (SO4·−) were found to be dominant in activating PS to accelerate the degradation of TC by reactive radicals. Moreover, the TC removal rate remained at 81.1 % after five cycles of degradation, indicating the satisfactory stability and reusability of the synthesized composite catalyst. Therefore, Mn-Ce/g-C3N4/PS/ViS system will be an effective option for antibiotic-containing wastewater treatment.

Attenuation of antibiotics from simulated swine wastewater using different microalgae-based systems

Antibiotic misuse are potentially harmful to the environment and human health. Four algal symbionts were constructed using Chlorella vulgaris, endophytic bacterium and Clonostachys rosea (C. rosea) as the biomaterials. The growth, photosynthetic activity, and antibiotic removal efficiency of symbiont under different initial antibiotic concentrations was analyzed. The results showed that the microalgae-bacteria-fungi symbiont had a maximum growth rate of 0.307 ± 0.030 d−1 and achieved 99.35 ± 0.47%, 81.06 ± 7.83%, and 79.15 ± 7.26% removal of oxytetracycline (OTC), sulfadimethazine (SM2), and ciprofloxacin hydrochloride (CPFX), respectively, at an initial antibiotic concentration of 0.25 mg/L. C. rosea has always existed as a biocontrol fungus. In this study, it was innovatively used to construct algal symbionts and used for antibiotic wastewater treatment with a high efficiency. The results contribute to the development of appropriate bioaugmentation strategies and the design of an algal symbiont process for the treatment of antibiotic-containing wastewater.

Sulfonated Hydrogel Formed via CO2-in-Water Emulsion: Potential in Antibiotic Removal.

Herein, a green, carbon dioxide-in-water high-internal-phase emulsion (C/W HIPEs) was developed and stabilized with polyvinyl alcohol (PVA) for the formation of chitosan oligosaccharide/poly(acrylamide-co-sodium 4-styrene sulfonate) [COS/P(AM-co-SSS)] monolithic porous hydrogel. The obtained monolith was characterized via FT-IR and SEM. The SEM patterns depicted that the monoliths were interconnected, the void sizes were 78.5 µm, and the interconnected pore throats were 28 μm approximately. Mechanical measurement results indicated that the maximum compress stress of the monolith could reach 334.4 kPa at 90% strain, and it exhibited good mechanical stability. After 200 cycles of compression, it could still recover its original shape without cracking. The obtained COS-based monolith was selected to remove tetracycline (TC) for evaluating the adsorptive features of the interpenetrating pore-containing monolith. The monolithic COS/P(AM-co-SSS) hydrogel behaved with strong antibiotic adsorption capacity (1600.4 mg/g for TC). The adsorption process agreed well with the pseudo-second-order kinetic and Langmuir isothermal models. In addition, the porous monolith had a strong electrostatic force on TC according to the thermodynamic study. This work provides a green route for the development of novel monolithic hydrogels and highlights its potential application in the treatment of antibiotic-containing wastewater.

Mechanisms and degradation pathways of doxycycline hydrochloride by Fe3O4 nanoparticles anchored nitrogen-doped porous carbon microspheres activated peroxymonosulfate

Peroxymonosulfate (PMS) based advanced oxidation processes have gained widespread attention in refractory antibiotics treatment. In this study, Fe3O4 nanoparticles anchored nitrogen-doped porous carbon microspheres (Fe3O4/NCMS) were synthesized and applied to PMS heterogeneous activation for doxycycline hydrochloride (DOX-H) degradation. Benefitting from synergy effects of porous carbon structure, nitrogen doping, and fine dispersion of Fe3O4 nanoparticles, Fe3O4/NCMS showed excellent DOX-H degradation efficiency within 20 min via PMS activation. Further reaction mechanisms revealed that the reactive oxygen species including hydroxyl radicals (•OH) and singlet oxygen (1O2) played the dominant role for DOX-H degradation. Moreover, Fe(II)/Fe(III) redox cycle also participated in the radical generation, and nitrogen-doped carbonaceous structures served as the highly active centers for non-radical pathways. The possible degradation pathways and intermediate products accompanying DOX-H degradation were also analyzed in detail. This study provides key insights into the further development of heterogeneous metallic oxides-carbon catalysts for antibiotic-containing wastewater treatment.

Efficient removal of tetracycline in water by a Fe3O4-mediated persulfate activation and biodegradation coupled system: Performance, validation, and mechanism

The cost-effective removal of antibiotic contaminants from the aqueous environment has become a hot research topic now. In this study, we proposed a novel coupled system, i.e., nano-Fe3O4 (nFe3O4) mediated persulfate (PDS) activation and biodegradation process, for efficient removal of tetracycline (TCH). The feasibility of the coupled system (nFe3O4 + PDS + microbe) was proved by comparing it with a single AOP (nFe3O4 + PDS) in batch and column experiments. The highest removal efficiencies of TCH (20 mg/L) and TOC reached 99.5 % and 43.2 % by the coupled system within 60 days. SEM spectra exhibited that nFe3O4 and microorganisms were well loaded on the non-woven fabric. Meanwhile, XPS results proved that more Fe(II) was on the surface of nFe3O4 in the coupled system than that in the single AOP. The presence of abundant Fe(II) in the coupled system suggested the potential electron transfer from Fe(III) with the assistance of microbes. High-throughput sequencing results indicated Proteobacteria played an important role in the coupled system. The degradation intermediates of TCH were analyzed by ultraperformance liquid chromatography-mass spectrometer (UPLC-MS), and reasonable degradation pathways were proposed. The coupling of nFe3O4 + PDS and biological treatment improved the TCH removal efficiency and reduced the burden of subsequent water treatment, which provided a feasible idea for the treatment of antibiotic-containing wastewater.

Treatment of antibiotic-containing wastewater with self-suspended algae-bacteria symbiotic particles: Removal performance and reciprocal mechanism

Emerging contaminants such as antibiotics in wastewater have posed a challenge on conventional biological treatment processes. Algae-bacteria symbiotic mode could improve the performance of biological treatment processes. Self-suspended algae-bacteria symbiotic particles (ABSPs) were prepared with Chlorella vulgaris and Bacillus subtilis using the sol-gel method and hollow glass microspheres in this study. The removal effect of nitrogen and phosphorus as well as the feedback mechanism of ABSPs under tetracycline stress were investigated through three-cycles wastewater treatment experiments. The antioxidant enzyme activity and phycosphere extracellular polymeric substance (EPS) content were identified as well. The results indicated that the removal rates of NH4+-N, TP, COD, and tetracycline in the ABSPs group finally reached 96.18%, 95.44%, 81.36%, and 74.20%, respectively, which were higher than the single algae group apparently. The phycosphere EPS content increased by 20.41% and algae cell structure maintained integrity in ABSPs group as compared with that in single algae group. This study demonstrates that the self-suspended ABSPs can improve contaminants removal performance and alleviate the antioxidant stress response of algae through algal-bacterial reciprocity mechanism.

Sustainable treatment of antibiotic-containing wastewater: Electric-assisted heterogeneous activation of peroxymonosulfate via recyclable Co2+/Co3+ conversion on S-doped CoO/Ti electrode

An electric-assisted peroxymonosulfate (PMS) activation system is developed for sustainable treatment of wastewater. S-doped CoO nanoflower grown on Ti plate (S-CoO/Ti) electrocatalyst is fabricated via one-step electrodeposition. S doping can increase the electron density of Co atoms, inclined to form Co2+ for PMS activation. The electrons from S-CoO/Ti cathode play dual roles: (1) directly activating PMS, and (2) promoting Co2+ regeneration for sustainable activation of PMS. The system generates energetic oxidative species (OH, SO4−, O2−, 1O2 and Co4+). Co4+ species accomplished via the reaction between Co2+ and PMS are dominantly responsible for tetracycline (TC) degradation. Almost 100% TC is removed within 20 min (C0 = 25 μM), and the toxicity of treated wastewater is reduced significantly. The S-CoO/PMS system exhibits a superior performance towards TC degradation in a wide pH range from 3 to 11. The removal of TC in natural water matrices reaches 97% within 30 min via continuous-flow process, showing 87% TOC removal within 2 h. Moreover, it remains highly stable lasting 60 h and the electric energy per order, which is much lower than that for advanced oxidation processes reported.

An FeP/carbon composite derived from a phytic acid-Fe3+ complex for sulfathiazole degradation through peroxymonosulfate activation

Peroxymonosulfate (PMS) activation-based advanced oxidation technology possesses great potential for antibiotic-containing wastewater treatment. Herein, we developed an iron phosphide/carbon composite and verified its capability and superiority towards a model antibiotic pollutant (sulfathiazole, STZ) degradation through PMS activation. Benefiting from the chelating ability of phytic acid (PA) with metal ions and its abundance on phosphorous element, a PA-Fe3+ complex was firstly formed and then served as sole precursor for iron phosphide formation by anoxic pyrolysis. Well crystalized FeP particle were found loading on the simultaneously formed thin layer carbon structure. Catalytic activity evaluation showed that FeP/carbon composite could remove over 99% of STZ (20 mg L−1) in 20 min adsorption and 30 min catalysis process under the reaction conditions of catalyst dosage 0.2 g L−1, PMS loading 0.15 g L−1. A pseudo-first-order reaction rate constant of 0.2193 min−1 was obtained, which was among the highest compared with reported studies. Further investigations indicated that the developed FeP/carbon composite worked well in a wide solution pH range of 3–9. Reaction mechanism study showed that reactive species of SO4−• and 1O2 generated from PMS activation played major roles for STZ degradation. Based on liquid chromatography-mass spectroscopy (LC-MS) analysis, a few STZ degradation intermediate products were identified, which facilitated the proposal of STZ degradation pathways. The possible ecological risk of STZ and related degradation intermediates were also considered by toxicity assessment using the Ecological Structure Activity Relationships (ECOSAR) Class Program. The obtained acute and chronic toxicity values implied the relatively low ecological risk of FeP/carbon-PMS reaction system for STZ treatment.

Insight into the microbial and genetic response of anammox biomass to broad range concentrations of different antibiotics: Linking performance and mechanism

Antibiotics have become emerging pollutants occurring in wastewater, influencing the activity of microorganisms responsible for wastewater treatment. Moreover, the potential application of the anammox process in the treatment of antibiotic-containing wastewater has paid much attention. A common antibiotic, OTC (oxytetracycline), CIP (ciprofloxacin), and CLA (clarithromycin) are recognized to be monitored in wastewater due to their relatively high concentration and hazardous impact on the environment. However, their effect on the anammox process remains unknown. Therefore, this paper presents the study concerning the long-term effects of a successive concentration of three antibiotics (OTC, CIP, CLA) on the anammox process, with special emphasis on treatment efficiency, resistance mechanism, bacteria cell morphology, and activated sludge community structure. It is worth noting that the influence of a successive concentration of CIP and CLA has been studied for the first time. Results revealed that anammox community could adapt to CIP, OTC, and CLA at low concentrations (<1 mg L-1), while the high concentration of antibiotics (100 mg L-1) reduced the nitrogen removal rate (NRR) by 27 % (OTC), 30 % (CIP), and 56 % (CLA). Community structure analysis showed that the abundance of Planctomycetes increased with the increase of CIP and CLA concentration while decreasing under OTC stress. On contrary, other nitrogen-cycle bacteria (e.g., Nitrospira) contributed to the nitrogen removal, especially during antibiotic suppression. The abundance of corresponding ARGs (OTC resistance gens: tetX, tetC, tetW, CIP resistance gens: qnrB4, qnrS, CLA resistance gens: mphA) generally increased under antibiotic suppression. In addition, co-occurrence analysis showed that anammox bacteria might participate in the transfer of macrolide resistance genes. The findings of this study are essential in understanding the mechanisms of three antibiotics commonly occurring in wastewater during the anammox process. Moreover, the results have implications for using the anammox process for antibiotic-containing wastewater treatment and provide the operational guidance for stable conducting of the anammox process under antibiotics suppression.

Highly Effective Removal of Ofloxacin from Water with Copper-Doped ZIF-8.

Residual antibiotics in wastewater have gained widespread attention because of their toxicity to humans and the environment. In this work, Cu-doped ZIF-8s (Cu-ZIF-8s) were successfully synthesized by the impregnation of Cu2+ in ZIF-8 and applied in the removal of ofloxacin (OFX) from water. Remarkably, excellent adsorption performance was obtained in Cu-ZIF-8s, especially for Cu-ZIF-8-1, in which the adsorption capacity (599.96 mg·g−1) was 4.2 times higher than that of ZIF-8 and superior to various adsorbents reported previously. The adsorption kinetics and adsorption isotherm follow the pseudo-second-order model and the Langmuir model, respectively. Furthermore, the removal efficiencies of OFX in Cu-ZIF-8-1 reached over 90% at low concentrations. It was revealed that electrostatic interaction and complexation play important roles in the adsorption process. In addition, the material can be regenerated by simple methods. Therefore, the obtained Cu-doped MOFs may have a promising application in the treatment of antibiotic-containing wastewater.

Hexadecyltrimethylammonium-activated and zinc oxide-coated nano-bentonite: A promising photocatalyst for tetracycline degradation

In the present work, we examined the UV-photocatalytic process of tetracycline degradation using the prepared nano-bentonite activated with hexadecyltrimethylammonium and coated with zinc oxide nanoparticles (HDTMA–BEN/ZnO) as a catalyst. The catalyst was analyzed and characterized using several analytical methods, including field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) method, diffuse reflection spectroscopy (DRS), and Fourier-transform infrared (FTIR) spectroscopy. The HDTMA–BEN/ZnO catalyst exhibited good efficiency for tetracycline degradation, with complete degradation at a pH of 9, tetracycline concentration of 20 mg/L, HDTMA–BEN/ZnO dose of 0.005 g/L, and reaction time of 180 min. From the results of the tetracycline degradation study, the degradation kinetics were consistent with the pseudo-first-order (PFO) equation. Moreover, from the reusability test results, the degradation after six cycles showed a mere 9% efficiency reduction. Furthermore, the removal efficiencies of chemical oxygen demand (COD) and total organic carbon (TOC) were 77.45% and 59.11%, respectively, implying that the suggested method resulted in a high mineralization rate. In conclusion, the UV-photocatalytic process using the HDTMA–BEN/ZnO catalyst exhibited appreciable effectiveness and applicability for the treatment of antibiotic-containing wastewater released from the pharmaceutical and industrial processes.

Microalgae simultaneously promote antibiotic removal and antibiotic resistance genes/bacteria attenuation in algal-bacterial granular sludge system

This study investigated the effects of microalgae growth on antibiotic removal and the attenuation of antibiotic resistance genes (ARGs)/ARGs host bacteria in algal-bacterial granular sludge (ABGS) system. In the presence of tetracycline (TC) and sulfadiazine (SDZ) mixture (2–4 mg/L), microalgae could grow on bacterial granular sludge (BGS) to form ABGS, with a chlorophyll-a content of 7.68–8.13 mg/g-VSS being achieved. The removal efficiencies of TC and SDZ by ABGS were as high as 79.0 % and 94.0 %, which were 4.3–5.0 % higher than those by BGS. Metagenomic analysis indicated that the relative abundances of TC/SDZ- related ARGs and mobile genetic elements (MGEs) in BGS were 56.1 % and 22.1 % higher than those in ABGS. A total of 26 ARGs were detected from the granules, and they were identified to associate with 46 host bacteria. 13 out of 26 ARGs and 13 out of 46 hosts were shared ARGs and hosts, respectively. The total relative abundance of host bacteria in BGS was 30.8 % higher than that in ABGS. Scenedesmus and Chlorella were the dominant microalgae that may reduce the diversity of ARGs hosts. Overall, ABGS is a promising biotechnology for antibiotic-containing wastewater treatment.

Cu-doped Fe2O3 nanoparticles/etched graphite felt as bifunctional cathode for efficient degradation of sulfamethoxazole in the heterogeneous electro-Fenton process

Bifunctional electrodes have attracted significant research interest in the field of heterogeneous electro-Fenton (hetero-EF) process for efficient treatment of antibiotic-containing wastewater. In this study, etched graphite felt (EGF) was used as the matrix material because of its excellent electrochemical properties, rich pore structure, and large specific surface area. The transition metals Cu and Fe were in situ grown on the EGF electrode surface without polymer binder by a one-step hydrothermal method. The obtained electrode consisting of Cu-doped Fe2O3 nanoparticles/EGF (Cu-Fe2O3/EGF) was used in the hetero-EF process for in situ electro-generation and activation of hydrogen peroxide (H2O2) for efficient degradation of sulfamethoxazole (SMX). The Cu-Fe2O3/EGF electrode demonstrated a wide pH application range of 3.0–9.0. According to electron spin resonance and free-radical quenching experiments, hydroxyl radical and superoxide anion were the dominant species in the hetero-EF process, while the hydroxyl radical played a major role in the degradation of SMX. In consecutive runs, the electrode exhibited low metal ion leaching and excellent stability. Furthermore, the possible mechanism for the production and activation of H2O2 as well as possible SMX degradation pathways were proposed. The toxicity of SMX samples during degradation exhibited a decreasing trend according to the results of toxicological simulation and Escherichia coli growth test. This study provides a new strategy for the construction of an efficient and stable bifunctional cathode for the advanced treatment of antibiotic-containing wastewater.

Adsorption performance of an amine-functionalized MCM–41 mesoporous silica nanoparticle system for ciprofloxacin removal

Antibiotic pollutants discharged from pharmaceutical industries are often present in the aquatic environment due to ineffective treatment of pharmaceutical wastewater and are hazardous to human and aquatic life. Therefore, effective treatment of antibiotic-containing wastewater is of utmost importance in the field of environmental protection. This study aims to evaluate the adsorption performance of an amine-functionalized MCM–41 mesoporous silica nanoparticles system (MCM–41–NH2) as an adsorbent for the removal of ciprofloxacin (CIP) antibiotic from aqueous solution. Surface and structural characteristics of MCM–41–NH2 were examined using scanning electron microscopy, X-ray diffraction, N2 adsorption–desorption analysis, Fourier transform infrared spectroscopy, and point of zero charge analysis. In addition, thermal stability was investigated by thermogravimetric analysis. Via the proposed treatment, 99.25% CIP removal was achieved under the following conditions: pH = 7; MCM–41–NH2 dose = 0.8 g/L; CIP concentration = 10 mg/L; adsorption time = 120 min; and shaking speed = 200 rpm. Isotherm study showed that the experimental data fitted well with the Langmuir equation. Moreover, the maximum adsorption capacity of MCM–41–NH2 for CIP was 164.3 mg/g. Thermodynamic parameters showed that the adsorption process of CIP on MCM–41–NH2 was endothermic and spontaneous. Additionally, the increase in solution temperature had a positive impact on the removal of CIP. The kinetic data obtained at different CIP concentrations (10, 25, 50, and 100 mg/L) were consistent with the pseudo-second-order model. MCM–41–NH2 could be recycled eight times in the proposed adsorption process, with a slight loss in its adsorption capacity. Compared with other adsorbents, MCM–41–NH2 was more effective for CIP removal.

Electrocatalytic oxidation of ciprofloxacin by Co-Ce-Zr/γ-Al2O3 three-dimensional particle electrode.

In this work, Co-Ce-Zr/γ-Al2O33 particle electrodes were prepared for the efficient degradation of ciprofloxacin (CIP). Co-Ce-Zr/γ-Al2O3 particle electrodes were analyzed with a scanning electron microscope (SEM), X-Ray Diffraction (XRD), X-Ray Fluorescence Spectrometer (XRF), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). According to the results, significant amounts of Co3O4, CeO2, and ZrO2 were formed on the Co-Ce-Zr/γ-Al2O3 particle electrodes. It was shown that when the conditions of the reaction system were at pH=6, conductivity of 4 ms/cm, current of 0.2 A, initial pollutant concentration of 100 mg/L, and material dosage of 15 g, CIP could be completely degraded within 40 min, and the energy consumed in the reaction was 41.3 kWh/kg CIP. The rate of total organic carbon (TOC) removal by Co-Ce-Zr/γ-Al2O3 particle electrodes was recorded to be approximately 52.6%. Using a response surface methodology, we explored the optimal operating conditions. At the same time, we also explored the influence of inorganic anions in water and actual water medium on the rate of CIP removal. In addition, the ESR data proved that the main active substance in the reaction system was ·OH. The degradation intermediates were investigated, and the possible mechanism was proposed. Thus, this research provided a new solution for the treatment of antibiotic-containing wastewater.

Fate of an antibiotic and its effects on nitrogen transformation functional bacteria in integrated vertical flow constructed wetlands

• IVCW could achieve simultaneous nitrogen and antibiotic removal. • Sulfamethoxazole (SMX) removal exceeds 95% primarily via biodegradation. • Enrichment of Pseudomonas , Bradyrhizobium , Sphingomonas , Luteimonas for SMX removal. • SMX transforms nitrogen transformation process to favor ANAMMOX. This study aims to provide insights into the fate and effects of the antibiotic sulfamethoxazole (SMX) on nitrogen transformation processes in integrated vertical-flow constructed wetlands (IVCW), which is useful to create strategies to improve their degradation and combat antibiotic resistance dissemination. Findings indicated chronic exposure to SMX to cause moderate deterioration of IVCW performance for nitrogen removal (p < 0.05), with average TN removal efficiency reductions of circa 10%. High-throughput sequencing and network analysis demonstrated chronic exposure of antibiotics to impact functional bacteria, ammonium oxidizing bacteria (AOB) and ANAMMOX, significantly. ANNAMMOX emerged as a potential pathway of nitrogen removal in the IVCW, albeit with considerable accumulation of NO 3 − -N (12.76 mg/L) and carbon deficiency (C/N = 0.99). Nonetheless, IVCW provides a promising technology for the advanced treatment of antibiotic-containing wastewater, demonstrated by a high and stable removal efficiency (circa 95%) of sulfamethoxazole. Biodegradation, primarily in the first stage of the IVCW, represented the major removal pathway of SMX. Microbial network analysis and the enrichment of Pseudomonas , Bradyrhizobium , Sphingomonas and Luteimonas demonstrated potential for the biodegradation of SMX. These results provide a theoretical reference for the enhancement of nitrogen and antibiotics removal in constructed wetlands.