Removal Efficiency Of Ciprofloxacin Research Articles

Durable fluorinated cobalt oxyhydroxide/calcium alginate hydrogels for activating peroxymonosulfate to enable nearly 100% degradation of ciprofloxacin.

Peroxymonosulfate (PMS) activation by solid catalysts for ciprofloxacin (CIP) removal is a promising method for decontaminating wastewater. However, mainstream catalysts suffer from efficiency and durability issues due to mechanical fragility and structural instability. Here, we have developed a durable calcium alginate hydrogel encapsulating fluorinated cobalt oxyhydroxide (FCO/CAH), fabricated by a simple hydrogen-bond-assisted cross-linking reaction, to enhance PMS activation for complete CIP removal. The optimized 2-FCO/CAH could generate abundant singlet oxygen (1O2) and sulfate radicals (SO4˙-) with PMS, resulting in 0.433 min-1 kinetic constant and approximately 100% CIP degradation within 10 minutes. This exceptional degradation efficiency is due to the even distribution of 2-FCO, which maximizes catalytic sites for PMS activation, and the multichannel cavity structure of CAH, which effectively enriches both PMS and CIP. Furthermore, the durability of 2-FCO/CAH was proved by its negligible decay in CIP removal efficiency (∼100%) and good microstructure retention after 6 consecutive cycles, facilitated by a stable surface reconstructed interphase on the 2-FCO surface and the strong mechanical property of 2-FCO/CAH. Our work showcases a facile approach to constructing durable hydrogel catalysts that improve PMS-mediated antibiotic degradation.

Adsorption behavior of graphite‐like walnut shell biochar modified with ammonia for ciprofloxacin in aqueous solution

AbstractBACKGROUNDGraphite‐like biochar of NWSC600K was prepared at 900 °C using walnut shell as the raw material and aqueous ammonia (NH3·H2O) as an activator, and characterized using transmission and scanning eletron microscopy (TEM, SEM), X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy and Fourier transform infrared (FTIR). The study investigated the adsorption performance and mechanism of NWSC600K for ciprofloxacin (CIP).RESULTSThe results showed that extremely tiny pores were found on the surface of NWSC600K, which increased its specific surface area to 823.91 m2 g−1, whereas the average pore size of NWSC600K decreased to 3.23 nm. The results of TEM, XRD and Raman spectroscopy detected well‐arranged lattice stripes as well as characteristic peaks corresponding to the graphite lattice appearing on the surface of NWSC600K. Moreover, the ID/IG value for NWSC600K was 1.429. The FTIR results showed that functional groups including the amino group were formed on NWSC600K.CONCLUSIONThe adsorption capacity of NWSC600K for CIP was 158.14 mg g−1 and the corresponding removal rate was 97.5% at pH 7. The pH value impact on the removal efficiency of CIP greatly, and the removal rate of CIP decreased linearly with increasing pH. The coexisting ions also would inhibit the adsorption of CIP on NWSC600K. Results obtained from kinetic and isotherm models, thermodynamics and characterization analyses suggested that pore‐filling, π–π stacking, hydrogen bonding, hydrophobicity and electrostatic interaction existed during the adsorption process. The adsorption was a nonspontaneous exothermic reaction. © 2024 Society of Chemical Industry (SCI).

Exploring the efficiency of nitrogenated carbon quantum dots/TiO2 S-scheme heterojunction in the photodegredation of ciprofloxacin in aqueous environments.

In this study, we developed a heterojunction photocatalyst, namely nitrogen-doped carbon quantum dots/titanium dioxide (N-CQDs/TiO2), for the effective and sustainable treatment of ciprofloxacin (CIP) antibiotic in aqueous solution. First, N-CQDs were prepared from a chitosan biopolymer with a green, facile, and effective hydrothermal carbonization technique and then anchored on the TiO2 surface via a hydrothermal process. The morphological, structural, and optical properties of the as-prepared materials were characterized by using advanced analytical techniques. The impacts of the mass percentage of N-CQDs, catalyst and CIP concentration, and pH on photocatalytic CIP degradation were investigated in depth. Comparative analyses were performed to evaluate different processes including adsorption, photolysis, and photocatalysis for the removal of CIP with TiO2 and N-CQDs/TiO2. The results revealed that N-CQDs/TiO2 exhibited the highest CIP removal efficiency of up to 83.91% within 120 min using UVA irradiation under optimized conditions (10 mg/L CIP, 0.4 g/L catalyst, and pH 5). Moreover, the carbon source used in the fabrication of N-CQDs was also considered, and lower removal efficiency was obtained when glucose was used as a carbon source instead of chitosan. This excellent improvement in CIP degradation was attributed to the ideal separation and migration of photogenerated carriers, strong redox capability, and high generation of reactive oxygen species provided by the successful construction of the N-CQDs/TiO2 S-scheme heterojunction. Scavenger experiments indicated that h+ and •OH reactive oxygen species were the predominant factors for CIP elimination in water. Overall, this study presents a green synthesis approach for N-CQDs/TiO2 heterojunction photocatalysts using natural materials, demonstrating potential as a cost-effective and efficient method for pharmaceutical degradation in water treatment applications.

Photo-Fenton like catalyst system with CuCOFe2O4@AC nanoparticles for ciprofloxacin removal from aqueous solutions and effluent toxicity assessment by Escherichia coli and Enterococcus faecalis bacteria

In this study, the removal of the antibiotic ciprofloxacin (CIP) from aqueous solutions was investigated using the Photo-Fenton like (PFL) process and CuCOFe2O4@AC (CAC) magnetic nanoparticles as catalysts. First, CAC nanoparticles were synthesized and their characteristics were determined by XRD, VSM and FESEM, EDS, Mapping, FTIR. The removal efficiency of CIP in each of the nanomaterial processes, including UV, H2O2, CAC, UV+H2O2, CAC+H2O2 (Fenton like), and UV+CAC+H2O2 (PFL), were 1.0%, 7.97%, 61.37%, 6.0%, 73%, and 84%, respectively. Therefore, the PFL process was optimized as a suitable process, and the optimal conditions were determined as follows: H2O2 concentration of 2500 mg/L, pH of five, CAC dose of 600 mg/L, CIP concentration of 15 mg/L, and contact time of 50 min. The removal efficiency of CIP was achieved at 95.99%. The kinetic studies on the PFL process for the removal of CIP shown that the first order kinetic model exhibits better compatibility with the obtained results compared to other investigated kinetic models. Furthermore, the synergistic effect of the PFL process was equivalent to 1.8 times the individual processes. The results of microbiological tests in treated wastewater samples and control sample indicate the non-toxicity of residual pharmaceuticals wastewater on E. coli and E. faecalis bacteria. Due to the non-toxicity of the wastewater and the ability to recover nanoparticles using magnetism, as well as the possibility of recycling the nanoparticles, this technique can be effectively used as a suitable process in pharmaceutical industry wastewater treatment.

Construction of a gelatin aerogel catalyst functionalized with LaCoO3 and g-C3N5 for efficient ciprofloxacin degradation via adsorption and peroxymonosulfate activation

Three-dimensional porous gelatin-based aerogels functionalized with LaCoO3 and nitrogen-rich graphitic carbon nitride (g-C3N5) were successfully fabricated via a freeze-drying approach. Herein, the gelatin-based aerogels served as excellent adsorbents and catalysts activating peroxymonosulfate (PMS) to efficiently degrade ciprofloxacin (CIP) from aqueous solutions. In comparison to the pristine gelatin aerogel (GA), the optimized functionalized aerogel (GA–LCCN-1.5) demonstrated a 17.0% superior CIP adsorption performance. Remarkably, GA–LCCN-1.5 exhibited 95.7% removal efficiency for CIP, attributed to the effective generation of •OH, SO4•−, and 1O2 via PMS activation. In addition, high degradation efficiencies over 84.1% were maintained throughout a broad pH range of 3–9. Notably, GA–LCCN-1.5 demonstrated outstanding stability and reusability, with 93.2% CIP removal efficiency even after five reuse cycles indicating significant promise in real applications. Radical quenching and electron spin resonance (ESR) analysis suggest that CIP degradation was dominated by radical and non-radical routes through GA–LCCN-1.5 catalyzed PMS decomposition. Besides, the plausible CIP degradation mechanisms were systemically analyzed and proposed. The toxicities of CIP and the intermediate by-products were evaluated and reported. The findings of this study and insights demonstrate a facile construction of a biopolymer-based aerogel catalyst for synergistic and efficient PMS activation for the removal of antibiotics in water.

Nickel-doped red mud-based Prussian blue analogues heterogeneous activation of H2O2 for ciprofloxacin degradation: waste control by waste.

Red mud (RM) is a typical bulk solid waste with Fe/Al/Si/Ca-rich characteristics that has been used to prepare various heterogeneous catalysts such as iron-based catalysts and supported catalysts. Prussian blue analogues (PBA) is a low-cost, environmentally friendly, and active site rich iron-based metal organic framework, but its catalytic properties are adversely affected by their easy aggregation. In this study, nickel-doped RM-based PBA (RM-Ni PBA) was synthesized by acid dissolution-coprecipitation method for the degradation of ciprofloxacin (CIP). The characterization showed that RM-Ni PBA was a material with excellent dispersibility, large specific surface area, and abundant active sites. The degradation results showed that the removal efficiency of CIP in the RM-Ni PBA/H2O2 system was 16.63, 1.78, and 1.81 times that of RM, RM-PB, and Ni PBA, respectively. It was found that 1O2 was the main reactive oxygen species (ROS) dominated the degradation process, and its formation was accompanied by the mutual conversion of Ni(II)/Fe(II) and Ni(III)/Fe(III). Notably, the degradation process maintained a satisfactory efficiency over a wide pH range (3-9) and exhibited strong anti-interference ability against impurities such as Cl-, SO42-, and NO3-. The components and contents of RM-Ni PBA remained relatively stable during the degradation process. In addition, the degradation intermediates of CIP were identified, and possible degradation pathways were proposed. This study is expected to provide theoretical basis and technical guidance for the application of RM-based heterogeneous catalyst in the treatment of antibiotic wastewater.

Solar photocatalytic degradation of ciprofloxacin using biochar supported zinc oxide- tungsten oxide photocatalyst.

Ciprofloxacin (CIP) is an antibiotic used to treat bacterial infections. It is not completely broken down during conventional wastewater treatment processes and can persist in the environment, leading to the development of antibiotic-resistant bacteria. This study focuses on the solar photocatalytic degradation CIP using biochar-supported photocatalysts. The photocatalysts developed by combining ZnO and WO3 in different ratios (1:2, 1:1, 2:1) were supported on hemp herd biochar. The photocatalyst made with a ratio of 2:1:1 of ZnO:WO3:biochar (Z2W1H) reported the highest CIP degradation efficiency of 87.3% and TOC removal efficiency of 43.1% at a catalyst dosage of 2g/L, initial CIP concentration of 3mg/L, and treatment time of 150min. Subsequently, the effects of operating parameters on CIP degradation were investigated using central composite design (CCD). About 85.4% degradation efficiency of CIP was obtained at optimum conditions (pH ∼8.4, initial CIP concentration ∼4.4mg/L, catalytic dosage ∼3.4g/L) within 90min. A quadradic model was developed to interpret the linear and interactive effect of operating parameters on the CIP degradation efficiency with 2.24-4.59% error. The adsorption-desorption study showed around 42.21% of adsorbed CIP was desorbed from Z2W1H. Scavenger studies demonstrated that the CIP breakdown was notably done by the superoxide radical (O2•-). The mechanism of CIP degradation was adsorption on biochar and subsequent degradation by photocatalyst. The prevalent degradation reactions such as C-N bond cleavage, decarboxylation, decarbonylation, defluorination, and ring opening lead to formation of various intermediates. The Z2W1H reusability test showed ~ 4.2% decrease in CIP removal efficiency after three cycles.

Valorization of coffee husks for the sustainable removal of pharmaceuticals from aqueous solutions

ABSTRACT The contamination of wastewater with pharmaceutical compounds represents a growing environmental challenge due to the inefficiency of conventional treatment systems in removing these emerging contaminants. The coffee husk (CH) is a promising bioadsorbent due to its abundant availability as a byproduct of coffee production. This study focuses on using untreated CH as an adsorbent for removing acetaminophen (ACE) and ciprofloxacin (CIP) while exploring the impact of pyrolysis temperature on the adsorption efficiency of these pharmaceutical compounds. The results reveal an excellent CH performance in removing CIP, achieving 64% removal with a maximum adsorption capacity of 37.00 mg/g. Increasing the pyrolysis temperature during the heat treatment of coffee husks significantly affects the adsorption of CIP. This behavior is primarily due to the reduction in functional groups, which are essential for facilitating the adsorption of CIP onto the resulting biochar. Thermodynamic parameters (ΔH° > 0 and ΔG° > 0) indicate that CIP adsorption on CH is an endothermic and not spontaneous process. The removal efficiency of CIP on CH for synthetic wastewater and urine matrices showed that CH can effectively remove CIP from wastewater. Finally, the reuse of CH as a bioadsorbent highlights its potential to contribute to water quality improvement and environmental preservation.

Oxygen Doping Cooperated with Co-N-Fe Dual-Catalytic Sites: Synergistic Mechanism for Catalytic Water Purification within Nanoconfined Membrane.

Atom-site catalysts, especially for graphitic carbon nitride-based catalysts, represents one of the most promising candidates in catalysis membrane for water decontamination. However, unravelling the intricate relationships between synthesis-structure-properties remains a great challenge. This study addresses the impacts of coordination environment and structure units of metal central sites based on Mantel test, correlation analysis, and evolution of metal central sites. An optimized unconventional oxygen doping cooperated with Co-N-Fe dual-sites (OCN Co/Fe) exhibits synergistic mechanism for efficient peroxymonosulfate activation, which benefits from a significant increase in charge density at the active sites and the regulation in the natural population of orbitals, leading to selective generation of SO4 •-. Building upon these findings, the OCN-Co/Fe/PVDF composite membrane demonstrates a 33min-1 ciprofloxacin (CIP) rejection efficiency and maintains over 96% CIP removal efficiency (over 24h) with an average permeance of 130.95Lm-2h-1. This work offers a fundamental guide for elucidating the definitive origin of catalytic performance in advance oxidation process to facilitate the rational design of separation catalysis membrane with improved performance and enhanced stability.

Enhanced removal of ciprofloxacin and associated antibiotic-resistant genes from wastewater using a biological aeration filters in combination with Fe3O4-modified zeolite.

Antibiotics release into the water environment through sewage discharge is a significant environmental concern. In the present study, we investigated the removal of ciprofloxacin (CIP) in simulated sewage by biological aeration filter (BAF) equipped with Fe3O4-modified zeolite (Fe3O4@ZF). Fe3O4@ZF were prepared with impregnation method, and the Fe3O4 particles were successfully deposited on the surface of ZF in an amorphous form according to the results of XPS and XRD analysis. The modification also increased the specific surface area (from 16.22 m²/g to 22 m²/g) and pore volume (from 0.0047 cm³/g to 0.0063 cm³/g), improving the adsorption efficiency of antibiotics. Fe3O4 modified ZF improved the treatment performance significantly, and the removal efficiency of CIP in BAF-Fe3O4@ZF was 79%±2.4%. At 10ml/L CIP, the BAF-Fe3O4@ZF reduced the relative abundances of antibiotics resistance genes (ARGs) int, mexA, qnrB and qnrS in the effluent by 57.16%, 39.59%, 60.22%, and 20.25%, respectively, which effectively mitigate the dissemination risk of ARGs. The modification of ZF increased CIP-degrading bacteria abundance, such as Rhizobium and Deinococcus-Thermus, and doubled bacterial ATP activity, promoting CIP degradation. This study offers a viable, efficient method to enhance antibiotic treatment and prevent leakage via sewage discharge.

Synthesis of MIL-53(Fe) implanted carbon spheres derived from resorcinol-formaldehyde resins for fast adsorption of antibiotics: Enhanced adsorption and pH adaptability

This article prepared a series of MIL-53(Fe) implanted carbon spheres derived from resorcinol-formaldehyde resins for rapid adsorption of Ciprofloxacin (CIP) using a facile hydrothermal coupling calcination methodology. Results indicated that MIL53(Fe)@RF-800, which was calcined at 800 °C, demonstrated the highest CIP removal efficiency of up to 95% within 60 min in batch adsorption tests. Moreover, MIL53(Fe) @RF-800 could remove over 95.8% of CIP at an amount of 0.2 mg/L, while both Cl− and HCO3− had a negligible impact on the CIP adsorption. It is noteworthy that when there was NO3− or SO42− in the solution, the impact of CIP adsorption displayed an inhibitory trend overall. In addition, MIL53(Fe)@RF-800 exhibited a broad pH range adaptability (over 95% CIP removal efficiency at pH = 3.0–10.5), even under highly acidic (pH < 3.0) or alkaline (pH > 10.5) conditions, the adsorption capacity for CIP was greater than 85%. In conclusion, this study provides novel insights into the development of highly porous MIL-53(Fe)-based adsorbent for rapid and pH-unrestricted adsorption of antibiotics and offers the possibility of practical engineering applications.

Sulfidated nano zero-valent iron activated peracetic acid for ciprofloxacin degradation: Performance and mechanism

As commonly observed water pollutants, antibiotics can induce antibiotic-resistance genes and pose significant risks to ecosystems and human health. Consequently, eliminating antibiotics from water environments is essential. We used the sulfidated nano zero-valent iron (S-nZVI) to activate peracetic acid (PAA) system to facilitate ciprofloxacin (CIP) degradation. S-nZVI was fabricated using the liquid-phase method, yielding particles with a predominantly spherical morphology and an average size range of 70–110 nm. Under optimized conditions, the S-nZVI/PAA system had a remarkable CIP removal efficiency of 95.61 % in 60 min. The reactive oxygen species (ROS) and Fe species (Fe(IV)) generated in the S-nZVI/PAA system were fundamental in facilitating the degradation of CIP. The reaction products of CIP were identified, and the toxicity was reduced after degradation. Additionally, an investigation was conducted to explore the practical application potential of the S-nZVI/PAA system. The work provides a promising strategy for the removal of antibiotics in water, and gives new insights into the mechanism of S-nZVI activating PAA to remove antibiotics.

Effects of Salts and Other Contaminants on Ciprofloxacin Removal Efficiency of Green Synthesized Copper Nanoparticles.

Ciprofloxacin (CIP), a broad-spectrum fluoroquinolone antibiotic, is commonly used in aquaculture to prevent and treat bacterial infections in aquatic animals. For this reason, aquatic environments contain CIP and its derivatives, which lead to the development of drug-resistant bacteria. In the present study, copper nanoparticles were prepared using Garcinia mangostana extract (GME-CuNPs) as a reducing agent and evaluated for their CIP removal efficiency (CRE). The results demonstrate that within 20 min, GME-CuNPs at 25 mM possess a CRE of 92.02 ± 0.09% from CIP-containing aqueous media with pH 6-7. The CRE is influenced by both monovalent and divalent salts. A high salt concentration significantly reduces the CRE. Contaminants in fish wastewater can reduce the CRE, but phenolics, flavonoids, tannins, and ammonia do not affect the CRE. Our results reveal that the CRE is controlled by electrostatic attraction between the negatively charged GME-CuNPs and the cationic species of CIP. The CRE is reduced by wastewater with a pH higher than 8.0, in which the CIP molecules have a negative charge, resulting in a repulsive force due to the negative charge of GME-CuNPs. In fish wastewater with a pH lower than 7.0, GME-CuNPs show the potential to achieve a CRE above 80%. Therefore, pH adjustment to a range of 6-7 in fish wastewater before treatment is deemed imperative. It is concluded that the newly developed GME-CuNPs possess excellent activity in CIP elimination from actual fish wastewater samples. Our findings suggest that GME-CuNPs can be a promising tool to effectively eliminate antibiotics from the environment.

Bamboo leaf-derived biochar/iron silicate composite for an adsorption-degradation synergistic removal of ciprofloxacin

Antibiotics pose significant risks to both the environment and human health. Herein, we develop a collaborative strategy for the enhanced removal of a typical antibiotic, Ciprofloxacin (CIP), by using a bamboo leaf-derived biochar/iron silicate composite (BL-FeSi) with the assistance of peroxymonosulfate (PMS). The rationale behind the design is the construction of composited material with synergistic adsorption-catalysis functions, based on covalent bonding networks of the biochar and specific Fe(III)/Fe(II) redox chemistry of iron silicate in PMS activation system. H2 reduction of pristine BL-FeSi increases Fe(II) content and thus improves catalytic activity. Batch experiments demonstrate that the preferred BL-FeSi400 (H2 treatment at 400 °C) exhibits superior efficiency in activating PMS. The CIP removal efficiency is highly dependent on pH value of reaction solution. A remarkable 97% removal is achieved at pH = 5.5 (CIP: 60 mL, 20 mg/L; BL-FeSi400: 0.2 g/L, PMS: 0.2 g/L), and the pH increase to 11 results in 100% CIP removal. The BL-FeSi400 shows robust resistance to inorganic ions (NO3−, SO42−, HCO3−, and H2PO4−), and the catalytic activity remains consistently high (>82%) even after four consecutive cycles, making it highly promising for practical applications. It is found that both radical pathway (•OH and SO4•−) and non-radical pathway (1O2) contribute to CIP degradation in the BL-FeSi400/PMS system, while the active •OH dominates the oxidization process. The coupling of adsorption and degradation holds great potentials for effective removal of more organic contaminants.

Modulating of Bi2MoO6-based photocatalyst through manipulation of reactant ratios for enhanced visible light photocatalytic activity

In this work, a novel photocatalyst, comprising of Bi2MoO6 and Bi2O2(OH)(NO3), was successfully synthesized by the one-pot hydrothermal method, thereby illuminating an innovative avenue for structure modulation of Bi2MoO6. The characterizations proved the facile attainability of controllable modifications in the microstructure and morphology of Bi2MoO6. The comprehensive appraisal of the synergistic adsorption-photocatalytic performances of the composites in the context of ciprofloxacin (CIP) was carried out. The findings presented compelling evidence that the amalgamation of Bi2MoO6/Bi2O2(OH)(NO3) exhibited an extraordinary adsorption capacity and photocatalytic activity when compared with the pristine Bi2MoO6 and Bi2O2(OH)(NO3). By virtue of its high surface area and pore volume, the optimized BMO/BON manifested a CIP adsorption capacity that surpassed that of Bi2MoO6 and Bi2O2(OH)(NO3) by approximately 2.4 and 11.2 times, respectively. Furthermore, through the concerted effects of adsorption and photocatalytic degradation, BMO/BON demonstrated an impressive CIP removal efficiency of 99.2 % following a mere 30 min of visible light exposure. The reaction rate constant was found to be approximately 0.124 min−1 for BMO/BON, surpassing that of Bi2MoO6 and Bi2O2(OH)(NO3). The augmentation in the photocatalytic activity of BMO/BON can be ascribed to its diminutive crystalline dimensions, large specific surface area, and narrowed bandgap. Thus, this investigation introduces a practical and ingenious strategy for the tuning of the Bi2MoO6 structure by manipulation of reactant ratios, showcasing significant implications in the realm of catalysis.

S-type heterojunction enhance the photocatalytic activity of TiO2/AgBr/Ag using loofah sponge as template towards ciprofloxacin degradation

Photocatalyst TiO2/AgBr/Ag (TBA) composites using loofah sponge as a template were successfully prepared for the first time. The photocatalytic activities of the TBA composites were evaluated by removing ciprofloxacin (CIP) under visible light. The PDOS shows that the valence band edge of TBA-30 is primarily composed of Ti 3d atom states, with small contributions from O 2p atom states. The conduction band edge is dominated by Ag 4d and O 2p atom states, with minor contributions from Br 4p atom states. TBA-30 composites demonstrate outstanding photocatalytic performance, degrading 87% of the target within 180 min. The degradation rate of CIP decreased to 70.19% after five runs, Furthermore, the TOC removal efficiency of CIP reached 84.2% in the end. CIP intermediates and degradation pathway were determined by GC-MS. Three-dimensional excitation-emission matrix fluorescence spectra (3D EEM) were used to study the degradation of CIP molecules. Trapping experiments and electron paramagnetic resonance (EPR) characterisation identified superoxide (·O2-) and photogenerated holes (h+) as the primary active radicals. Furthermore, formed S-type heterojunction and Ag as the electron capture site enhanced the separation efficiency of photoinduced electron-hole pairs. The DFT calculation was used to study the electron transport performance of TBA-30 by calculating the charge density difference.

Hydroxyapatite incorporated metakaolin/sludge based geopolymer adsorbent for copper ions and ciprofloxacin removal: Synthesis, characterization and mechanisms

The efficacy of copper Cu(II) adsorption is significantly affected by the presence of antibiotics, such as ciprofloxacin (CIP). Therefore, researchers are highly interested in conducting extensive investigations on the simultaneous adsorption of Cu(II) and CIP. However, most of the adsorbents exhibited low adsorption capacity of CIP with increasing Cu(II) concentration due to the competition for adsorption sites. Hence, the integration of various adsorbents into a single composite could be an effective way to increase the adsorption sites. Thus, this study aims to incorporate hydroxyapatite (Hap) into metakaolin/sludge based geopolymer adsorbent for simultaneous adsorption of Cu(II) and CIP. The effect of different filler loading of Hap (1–3 %) on the metakaolin/sludge geopolymerization and also on the removal efficiency of Cu(II) and CIP were studied in a single and binary system. Moreover, the effects of varied concentrations of Cu(II) (0–100 mg/L) on the removal efficiency of CIP were investigated. Characterization techniques such as x-ray diffraction (XRD), fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), brunauer-emmett-teller (BET) and neutron tomography imaging were employed to characterize the physicochemical properties of the synthesized geopolymer. It was found that the Hap content has a significant impact on the removal efficiency of CIP and Cu(II). The addition of 2 % Hap providing more nucleation site for the increasing geopolymerization (C-A-S-H) and silicoalumino phosphate gel (SAP) leading to the formation of highly cross-linked geopolymer network and abundant active sites which would favour the adsorption. Moreover, the removal efficiency of CIP by 2 % Hap-geopolymer increased (25.6 % to 61.51 %) with increasing Cu(II) concentration by the complexation and bridging effect between Cu(II) and CIP resulting in the formation of GMK25S1-2Hap-Cu(II)-CIP complexes. Therefore, the hybrid method of geopolymer and Hap is an exceptionally efficient approach for the treatment of wastewater that comprises Cu(II) and CIP.

Application of CuFeLDH-NCNT in ultrasound-assisted-Fenton-like process for removing ciprofloxacin from aqueous solutions.

In this study, the mesoporous material NCNT was prepared by treating carbon nanotubes (CNT) with hydrazine and subsequently loaded with Cu-Fe layered double hydroxide (CuFeLDH) to create a multiphase catalyst (CuFeLDH-NCNT). Its application as a multiphase catalyst was investigated in an ultrasound-assisted Fenton process for ciprofloxacin (CIP) degradation in aqueous solution. In addition, the impacts of catalyst dosage, ultrasonic power, H2O2 dosage, and beginning pH on CIP removal efficiency were carefully evaluated to maximize the removal efficiency of CIP. The findings indicated that the elimination rate of the initial CIP concentration of 20 mg/L surpassed 94.66% after a mere 100 min, while the TOC degradation rate was 70.4%. The high removal rate was due to the synergistic action between the nanoparticles, H2O2, and ultrasonography. The degradation intermediates of CIP were examined, and putative degradation pathways and mechanisms were postulated.

Safe Disposal of Accident Wastewater in Chemical Industrial Parks Using Non-Thermal Plasma with ZnO-Fe3O4 Composites.

Chemical wastewater has a high concentration of toxic and hazardous antibiotic pollutants, which not only devastates the ecological environment and disrupts the ecological balance, but also endangers human health. This research proposed a non-thermal plasma (NTP) combined with a ZnO-Fe3O4 nano-catalyst system to achieve the efficient degradation of ciprofloxacin (CIP) in chemical wastewater. Firstly, ZnO-Fe3O4 composite materials were prepared using hydrothermal method and characterized with scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), etc. With the sole NTP, NTP/ZnO, and NTP/ZnO-Fe3O4 systems, the removal efficiency of CIP can reach 80.1%, 88.2%, and 99.6%, respectively. The optimal doping amount of Fe3O4 is 14%. Secondly, the capture agent experiment verified that ·OH, ·O2-, and 1O2 all have a certain effect on CIP degradation. Then, liquid chromatography-mass spectrometry (LC-MS) was used to detect the intermediate and speculate its degradation pathway, which mainly included hydroxyl addition, hydroxyl substitution, and piperazine ring destruction. After treatment with the NTP/ZnO-Fe3O4 system, the overall toxicity of the product was reduced. Finally, a cyclic experiment was conducted, and it was found that the prepared ZnO-Fe3O4 catalyst has good reusability. The NTP/ZnO-Fe3O4 was also applied in practical pharmaceutical wastewater treatment and has practical applicability.

Optimizing ciprofloxacin removal through regulations of trophic modes and FNA levels in a moving bed biofilm reactor performing sidestream partial nitritation

The performance of partial nitritation (PN)-moving bed biofilm reactor (MBBR) in removal of antibiotics in the sidestream wastewater has not been investigated so far. In this work, the removal of ciprofloxacin was assessed under varying free nitrous acid (FNA) levels and different trophic modes. For the first time, a positive correlation was observed between ciprofloxacin removal and FNA levels, either in the autotrophic PN-MBBR or in the mixotrophic PN-MBBR, mainly ascribed to the FNA-stimulating effect on heterotrophic bacteria (HB)-induced biodegradation. The maximum ciprofloxacin removal efficiency (∼98 %) and removal rate constant (0.021 L g−1 SS h−1) were obtained in the mixotrophic PN-MBBR at an average FNA level of 0.056 mg-N L−1, which were 5.8 and 51.2 times higher than the corresponding values in the autotrophic PN-MBBR at 0 mg FNA-N L−1. Increasing FNA from 0.006 to 0.056 mg-N L−1 would inhibit ammonia oxidizing bacteria (AOB)-induced cometabolism and metabolism from 10.2 % and 6.9 % to 6.2 % and 6.4 %, respectively, while HB-induced cometabolism and metabolism increased from 31.2 % and 22.7 % to 41.9 % and 34.5 %, respectively. HB-induced cometabolism became the predominant biodegradation pathway (75.9 %-85.8 %) in the mixotrophic mode. Less antimicrobial biotransformation products without the piperazine or fluorine were newly identified to propose potential degradation pathways, corresponding to microbial-induced metabolic types and FNA levels. This work shed light on enhancing antibiotic removal via regulating both FNA accumulation and organic carbon addition in the PN-MBBR process treating sidestream wastewater.