Ciprofloxacin Removal Research Articles

Application of Ce2(WO4)3–ZnO–CuO nanocomposite as active photocatalyst for removal of ciprofloxacin from wastewater

In this study, the synthesis of Ce2(WO4)3/ZnO/CuO nanocomposite (NCs) was carried out using Co-precipitation method. The structural, morphological and spectral confirmation was achieved through X-ray diffraction (XRD), Scanning electron microscopy (SEM), Differential reflectance spectroscopy (DRS) and Fourier transform infrared spectroscopy (FTIR) analysis. The degradation efficiency for photocatalytic degradation of Ciprofloxacin (CF) and band gap value of prepared Ce2(WO4)3/ZnO/CuO nanocomposite was determined by using UV–Visible and DRS analysis. Band gap value for Ce2(WO4)3/ZnO/CuO was found to be 1.39 eV. Effects of different parameters such as contact time, pH, and effect of concentration of catalyst were investigated to optimize degradation conditions. This prepared nanocomposite was used for the degradation of CF and about 91 % degradation efficiency of CF has been achieved at pH 5 within 70 min by irradiation under sunlight and 60 mg concentration of photocatalyst. The EDTA and IPA scavenged photo-generated holes and hydroxyl ions respectively, the decrease in photocatalytic degradation indicates that holes and hydroxyl ions are reactive species in photocatalytic degradation of CF. The value of R2 = 0.99 confirms the validity of Pseudo first order and Langmuir-Hinshelwood kinetic model for the degradation of CF. These results showed a novel method for the preparation of nanocomposite and the efficient degradation of antibiotics and can be applied to industrial manufacture.

Periodate-driven efficient degradation of diverse pharmaceuticals with iodine-doped MnO2

This research investigated the development of a novel catalyst for contaminant remediation. The strategy involved enhancing the catalytic effectiveness of MnO2 by strategically incorporating iodine, resulting in I-MnO2. Electron paramagnetic resonance (EPR) spectroscopy confirmed an augmentation in oxygen vacancies upon iodine inclusion, leading to increased catalytic activity. I-MnO2 was evaluated as an efficient catalyst within an advanced oxidation process for ciprofloxacin removal through periodate activation. The system achieved a 91.2 % degradation of 20 ppm ciprofloxacin within 9 min, demonstrating a strong correlation between catalyst and oxidant dosages. The I-MnO2/IO4¯ system exhibited remarkable stability across a broad pH range and minimal susceptibility to ionic strength variations, water anions, and humic acid presence. Quenching experiments coupled with EPR analysis suggested the involvement of singlet oxygen (1O2) and iodate radicals (IO3•) generated from the interaction of the metastable Mn(IV)-O-IO3 species with ciprofloxacin. X-ray photoelectron spectroscopy analysis of Mn 2p and O 1s orbitals, performed before and after reactions, further corroborated the role of I-MnO2 in facilitating periodate activation by promoting the conversion of Mn(II) and Mn(III) to Mn(IV) species. This innovative catalyst demonstrates exceptional efficiency in eliminating high concentrations of organic pollutants, suggesting its potential for practical and cost-effective applications in wastewater treatment.

Insights into the role of electrochemical stimulation on sulfur-driven biodegradation of antibiotics in wastewater treatment

The presence of antibiotics in wastewater poses significant threat to our ecosystems and health. Traditional biological wastewater treatment technologies have several limitations in treating antibiotic-contaminated wastewaters, such as low removal efficiency and poor process resilience. Here, a novel electrochemical-coupled sulfur-mediated biological system was developed for treating wastewater co-contaminated with several antibiotics (e.g., ciprofloxacin (CIP), sulfamethoxazole (SMX), chloramphenicol (CAP)). Superior removal of CIP, SMX, and CAP with efficiencies ranging from 40.6 ± 2.6 % to 98.4 ± 1.6 % was achieved at high concentrations of 1000 μg/L in the electrochemical-coupled sulfur-mediated biological system, whereas the efficiencies ranged from 30.4 ± 2.3 % to 98.2 ± 1.4 % in the control system (without electrochemical stimulation). The biodegradation rates of CIP, SMX, and CAP increased by 1.5∼1.9-folds under electrochemical stimulation compared to the control. The insights into the role of electrochemical stimulation for multiple antibiotics biodegradation enhancement was elucidated through a combination of metagenomic and electrochemical analyses. Results showed that sustained electrochemical stimulation significantly enriched the sulfate-reducing and electroactive bacteria (e.g., Desulfobulbus, Longilinea, and Lentimicrobiumin on biocathode and Geobactor on bioanode), and boosted the secretion of electron transport mediators (e.g., cytochrome c and extracellular polymeric substances), which facilitated the microbial extracellular electron transfer processes and subsequent antibiotics removal in the sulfur-mediated biological system. Furthermore, under electrochemical stimulation, functional genes associated with sulfur and carbon metabolism and electron transfer were more abundant, and the microbial metabolic processes were enhanced, contributing to antibiotics biodegradation. Our study for the first time demonstrated that the synergistic effects of electrochemical-coupled sulfur-mediated biological system was capable of overcoming the limitations of conventional biological treatment processes. This study shed light on the mechanism of enhanced antibiotics biodegradation via electrochemical stimulation, which could be employed in sulfur-mediated bioprocess for treating antibiotic-contaminated wastewaters.

Endogenous iron-enriched biochar loaded nickel-foam cathode in electro-Fenton for ciprofloxacin degradation: performance, mechanism and DFT calculation

Steel mill wastewater sludge, with abundant endogenous iron resources, could be pyrolyzed into iron-enriched biochar (SBC) in one step and loaded onto nickel foam cathode (Ni-Foam) to construct a heterogeneous electro-Fenton system (SBC@Ni-Foam/EF). The purpose of this study were to optimize SBC@Ni-Foam/EF for efficient ciprofloxacin (CIP) removal, and its degradation mechanism and pathway in the presence of endogenous iron were elucidated by DFT calculation. The results showed that the highest CIP degradation efficiency (95.11 %) was achieved at a SBC pyrolysis temperature of 800 °C, an initial solution pH of 3, a Na2SO4 concentration of 0.05 mol L−1, a current density of 40 mA cm−2, and an aeration rate of 200 mL min−1. The degradation of CIP by SBC@Ni-Foam/EF was dominated by cathodic catalytic oxidation, and ·OH played a major role in the CIP degradation process. Combined with characterization and DFT calculation, the endogenous iron was dispersed in the stable Fe3O4 crystalline phase, which provided surface defects and catalytic sites for the cathode and promoted H2O2 activation to generate ·OH through iron cycling. The possible degradation pathways of CIP were proposed to include the cleavage of piperazine and quinolone rings, hydroxylation, and substitution or detachment of fluorine, etc., and the overall toxicity of the intermediates was alleviated after SBC@Ni-Foam/EF treatment. Therefore, this study was expected to achieve a win–win situation for iron-enriched sludge biomass resource utilization and CIP wastewater treatment.

Photocatalytic removal of ciprofloxacin using synthesized of C/Fe-BiVO4/Bi2WO6 photocatalysts: Optimization and modeling of process by RSM and ANN

A novel heterogeneous photocatalyst based on a combination of C/Fe, BiVO4, and Bi2WO6, exhibiting characteristics of a Fenton-like catalyst, was synthesized using a two-step process involving the carbonization of the resin followed by a hydrothermal treatment. Comprehensive analysis revealed that the increased dispersion of C/Fe-BiVO4/Bi2WO6 particles and the expanded BET surface area of the C/Fe-BiVO4/Bi2WO6 catalyst enhanced its catalytic efficiency in breaking down ciprofloxacin (CIP) compared to C/Fe-BiVO4 and C/Fe-Bi2WO6. Two efficient methods, namely response surface methodology (RSM) and artificial neural networks (ANNs), were engaged to design and refine the photocatalytic process. Under optimal RSM conditions (10 mg·L−1 CIP, 0.75 g·L−1 catalyst, H2O2 dose, 200 mg·L−1 at pH=5.0 within 30 min), CIP's elimination efficiency reached 94.92 %. Based on the ANN analysis, the relative importance of process-influencing parameters was: pH (82.3 %), H2O2 concentration (6.8 %), C/Fe-BiVO4/Bi2WO6 catalyst dosage (7.5 %), and CIP initial concentration (3.4 %). The C/Fe-BiVO4/Bi2WO6 demonstrated remarkable reusability and robust stability through its recycling degradation process. Additionally, the study focused on the photocatalytic breakdown process and the by-products of ciprofloxacin degradation. The results indicated that the·OH and·O2- are play a significant role in the photocatalytic oxidation of CIP. Eight distinct products were identified as degradation products.

Excellent performance of a new stable LaCaCuFeO3 catalyst for the simultaneous removal of fluoroquinolone organic compounds in wastewater

This study designed LaCaCuFeO3 (LCCFO) by incorporating Ca into A sites of LaCuFeO3 (LCFO). LCCFO could efficiently activate peroxydisulfate (PDS) to simultaneous removal multiple fluoroquinolone organic compounds (FQs) in wastewater. In comparison to LCFO, the LCCFO could degrade 80 % of ciprofloxacin (CIP) and 100 % of ofloxacin (OFX) in 2 h with acceptable ion leaching. After four cycles, LCCFO retained its exceptional catalytic performance. During the reaction, the pHreaction increased from 4.4 to 6.7. Adjusting the pHreaction to 4.4 again at the end of the reaction could remove residual FQs. These findings provided a new insight into the treatment of wastewater with lower addition of PDS. Although the effects of inorganic anions on the removal of CIP and OFX were different, high concentration of Cl−, SO42−, HCO3− and H2PO4− at 10 g/L had a slight inhibitory effect on the reaction. The coexistence of radical and nonradical reaction pathways contributed to its excellent hypersaline tolerance. The LCCFO possessed good application prospects in wastewater treatment with hypersaline and complex pollutants.

Preparation of MoS2/V2O5 nanocomposites for ciprofloxacin degradation and Cr (VI) reduction

In this study, MoS2/V2O5 nanocomposites are obtained by hydrothermal process, and used for photocatalytic system of Ciprofloxacin (CIP) degradation and Cr (VI) reduction. Owing to its novel characteristics, MoS2/V2O5 heterojunctions are revealed as potential semiconductors in this region. V2O5 photocatalyst acts as a charge acceptor, meantime MoS2 acts as an electron donor, therefore promoting charge carrier separation and enhancing photocatalytic efficiency. The MoS2/V2O5 nanocomposites displayed enhanced photocatalytic CIP (98.7 %) and Cr (VI) reduction (98.8 %) after 120 min and 100 min of visible light activity. In contrast, in the first cycle, the photocatalysis capability of the photocatalyst performed in six cycles is 93.8 %. The Kapp values of MoS2/ V2O5 nanocomposites displayed about 11.2 and 19.5-times improvement of photocatalytic of CIP degradation and Cr (VI) reduction, respectively. The MoS2/V2O5 nanocomposites exhibited an enhanced photocurrent density of 0.082 μA/cm−2 compared to a pristine MoS2 sample of 0.045 μA/cm−2. The distinguished heterojunction photocatalysis performance is due to the significant migration of interfacial charges and the inhibited recombination rate of electron-hole pairs. CIP Pollutants eventually decay into H2O, CO2, and small molecule intermediates by generating •O2-, •OH, and h+. The influences of reactive radicals follow the order of •O2- radicals > h+ radicals > •OH radicals. Then, the probable structures of intermediates and achievable photodegradation pathways were discussed for the removal of CIP and Cr (VI) reduction using nanocomposite with visible light response.

BiVO4/sulfur-doped g-C3N4 nanocomposite as photocatalyst for degradation of ciprofloxacin under visible light irradiation

In recent years, the use of antibiotics has greatly increased, which has caused environmental pollution. We offer a photocatalyst based on BiVO4/sulfur-doped g-C3N4 nanocomposite, which was made by a one-step thermal condensation method from thiourea and bismuth vanadate to degradate ciprofloxacin (CIP). The BiVO4/sulfur-doped g-C3N4 photocatalyst was analyzed by certain techniques including XRD, FTIR, BET, FESEM, EDX, TEM, DRS, photoluminesence, and Mott-Schottky to determine various physicochemical properties. The photocatalytic degradation of CIP, as a model pollutant, under visible LED light irradiation was tested to investigate the catalytic performance of nanocomposite. Response Surface Methodology (RSM) was employed to optimize operational parameters, including photocatalyst dosage (50–150 mg), CIP concentration (10–30 mg/L), initial pH of the solution (3–11), and irradiation time (12–120 min). The BiVO4/sulfur-doped g-C3N4 nanocomposite, with a narrow bandgap of 2.15 eV, exhibited exceptional photocatalytic performance in degrading CIP. The optimal conditions for CIP removal were photocatalyst dosage of 120.9 mg, CIP concentration of 10 mg/L, and initial solution pH of 3, resulting in 93.5 % removal efficiency after 105 min of irradiation. The photocatalytic degradation kinetics of CIP followed a pseudo-first-order model with a rate constant (K) of −0.0221 L/min, indicating rapid degradation process. The photocatalyst maintained excellent performance after 5 reuses, with only a 3 % reduction in efficiency. XRD analysis confirmed the structural stability of the nanocomposite after reuse.

Effect of environmental factors on adsorption of ciprofloxacin from wastewater by microwave alkali modified fly ash

Antibiotics, as emerging persistent pollutants, pose significant threats to human health. The effective and low-cost removal of ciprofloxacin (CIP) from wastewater has become an important research focus. In this study, fly ash (FA) was used as the raw material, and modified fly ash (MFA) was prepared by varying microwave power, alkali concentration, and immersion time to investigate its adsorption characteristics for CIP. Results showed that the optimal preparation conditions for MFA with the most effective adsorption of CIP, using the Box-Behnken response surface methodology, were a microwave power of 480 W, an alkali concentration of 1.5 mol/L, and a modification time of 3 h. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analyses revealed that after modification, the glassy structure of FA is destroyed, the specific surface area is increased, and obvious hydroxyl O–H absorption peaks appear. Both FA and MFA exhibited adsorption processes for CIP that conformed to pseudo-second-order kinetics and the Langmuir equation. Maximum adsorption of CIP (9.61 and 12.67 mg/g) was achieved at pH = 6. With increasing temperature, the adsorption capacity of both FA and MFA for CIP decreased, indicating an exothermic process. The adsorption capacity of CIP decreased with increasing ion concentration, with the impact order of ions being Al3+ > Ca2+ > Na+. The results show that pore filling, electrostatic interaction, ion exchange and complexation are the main ways of CIP adsorption by FA. Microwave alkali modified fly ash is an economical and efficient adsorbent for CIP removal in water, realizing the purpose of “treating waste with waste”. This study provides a scientific basis for controlling CIP treatment in wastewater.

Banana Peel Extract-Derived ZnO Nanopowder: Transforming Solar Water Purification for Safer Agri-Food Production.

Pure water scarcity is the most significant emerging challenge of the modern society. Various organics such as pesticides (clomazone, quinmerac), pharmaceuticals (ciprofloxacin, 17α-ethynilestradiol), and mycotoxins (deoxynivalenol) can be found in the aquatic environment. The aim of this study was to fabricate ZnO nanomaterial on the basis of banana peel extract (ZnO/BPE) and investigate its efficiency in the photocatalytic degradation of selected organics under various experimental conditions. Newly synthesized ZnO/BPE nanomaterials were fully characterized by the XRD, FTIR, SEM-EPS, XPS, and BET techniques, which confirmed the successful formation of ZnO nanomaterials. The photocatalytic experiments showed that the optimal catalyst loading of ZnO/BPE was 0.5 mg/cm3, while the initial pH did not influence the degradation efficiency. The reusability of the ZnO/BPE nanomaterial was also tested, and minimal activity loss was found after three photocatalytic cycles. The photocatalytic efficiency of pure banana peel extract (BPE) was also studied, and the obtained data showed high removal of ciprofloxacin and 17α-ethynilestradiol. Finally, the influence of water from Danube River was also examined based on the degradation efficiency of selected pollutants. These results showed an enhanced removal of ciprofloxacin in water from the Danube River, while in the case of other pollutants, the treatment was less effective.

Adsorption of ciprofloxacin from aqueous solutions using cellulose-based adsorbents prepared by sol-gel method

Ciprofloxacin (CIP) is one of the most widely used antibiotics to treat bacterial infections. Consequently, there is concern that it may contaminate water resources due to its high usage level. It is therefore necessary to monitor, trace, and reduce exposure to these antibiotic residues. In the current study, the extraction of CIP from water was performed using a green adsorbent material based on cellulose/polyvinyl alcohol (PVA) decorated with mixed metal oxides (MMO). This cellulose/MMO/PVA adsorbent was synthesized using a simple sol-gel method. The prepared adsorbent materials were then characterized using a range of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, gas adsorption analysis, X-ray diffraction, and Fourier Transform infrared. The impact of pH, adsorbent dose, contact time, and CIP concentration on ciprofloxacin extraction were examined. The equilibrium and kinetic adsorption data were well described using the Freundlich model (R2 = 0.965). The optimum conditions for CIP adsorption were: pH = 4.5; adsorbent dosage = 0.55 g·L−1; contact time = 83 min; and initial CIP concentration = 2 mg·L−1. The adsorption capacity of the cellulose/MMO/PVA adsorbent for CIP removal was ∼19 mg·g−1 (CIP removal = 86.48 %). This study shows that cellulose/MMO/PVA adsorbents have potential for removing contaminants from aqueous environments.

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.

High-carbon-content biochar from chemical manufacturing plant sludge for effective removal of ciprofloxacin from aqueous media

Biochar is considered a promising biosorbent for harmful organic pollutants in aqueous media. However, only a limited number of biochars derived from industrial sludges have been utilized due to their problematic high ash content and heavy metal leaching. In this study, a highly effective biochar was prepared as a superabsorbent for ciprofloxacin (CIP) from chemical manufacturing plant sludge via K2CO3-activated pyrolysis, and its CIP removal behavior was evaluated. Unlike sewage sludge, chemical manufacturing plant sludge contains low SiO2, resulting in an ultra-pure carbon (95.4%) based biochar with almost negligible ash content. As the pyrolysis temperature increased from 400 to 800 °C, the ordered graphitic carbon structure transformed into an amorphous carbon phase, and most oxygen-containing groups disappeared. However, the pore size significantly decreased to ∼4.5 nm due to the corrosive carbon volatilization caused by K2CO3, resulting in an extremely large surface area of 2331.8 m2/g. Based on its large surface area and porous carbon structure, the activated biochar at 800 °C (CAB-800) exhibited an outstanding CIP adsorption capacity of 555.56 mg/g. The CIP adsorption isotherm, kinetic, and thermodynamic studies were systematically investigated. The CIP adsorption on CAB-800 was mainly attributed to π-π interactions and hydrogen bond formation, with electrostatic interactions partially contributing to the adsorption reaction. From pH 2 to 12, CAB-800 showed an excellent CIP adsorption capacity of over 316.7 mg/g, with adsorption favored under acidic conditions. Except for HCO3− and CO32−, the presence of anions and humic acids did not significantly affect CIP adsorption capacity. These results demonstrate that biochar produced from chemical manufacturing industry sludge via K2CO3 activation is a highly feasible material for the removal of CIP from aqueous media.

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.

Removal of ciprofloxacin via enhancing hydrophilicity of membranes using biochar

Growing concerns regarding the presence of pharmaceuticals in wastewater necessitate their removal. Membrane filtration offers a promising approach. This study explores the development of biochar incorporated mixed matrix membranes (MMMs) for ciprofloxacin removal from water. Biochar, derived from the pyrolysis of agricultural waste, was blended with polyether sulfone (PES) and polyvinylpyrrolidone in varying ratios. The resulting MMMs exhibited progressively improved properties with increasing biochar content. Notably, membrane M11, comprising equal parts PES and biochar, displayed the highest porosity, lowest surface roughness (12.0), and lowest contact angle (31.05°), indicating enhanced hydrophilicity (increased by 58.19% compared to the biochar-free membrane). M11 effectively removed ciprofloxacin along with three additional antibiotics from different classes. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses corroborated the removal of ciprofloxacin. Furthermore, M11 demonstrated excellent regenerability, retaining over 57% removal efficiency after four cycles. These findings highlight the potential of M11 as a sustainable and cost-effective membrane for pharmaceutical removal from wastewater.

Antibiotic Removal by Three Promising Microalgae Strains: Biotic, Abiotic Routes, and Response Mechanisms

Microalgae represent an alternative to conventional wastewater treatment, potentially improving antibiotic removal and offering a solution to combat the spread of antimicrobial resistance. Through batch assays, this study investigates the routes for antibiotic removal using three strains (Chlamydomonas acidophila, Auxhenochlorella protothecoides and Tetradesmus obliquus). Using mixtures of ciprofloxacin, clarithromycin, erythromycin, metronidazole, ofloxacin, sulfamethoxazole, and trimethoprim at concentrations simulating wastewater composition, it also assesses antibiotic effects on microalgae physiology. The three strains primarily removed antibiotics through rapid biosorption, achieving up to 91.5% removal for specific ones like ciprofloxacin. T. obliquus and C. acidophila showed efficacy, with total removals of 37.2% and 49.3%, respectively. Over time, A. protothecoides demonstrated the highest active removal efficiency, eliminating 22.1% of total antibiotics, with a notable 67.6% removal for sulfamethoxazole. Abiotic degradation through hydrolysis and photolysis contributed to ciprofloxacin, ofloxacin, clarithromycin, and erythromycin removal (34.7% to 96.7%), showing pH-dependent photolysis. However, algae induced a shading effect, reducing the photolytic and hydrolytic degradation of specific antibiotics. T. obliquus and C. acidophila were inhibited by antibiotics, whereas A. protothecoides showed a 30.6% growth rate increase. The stimulatory effect was also observed for the nutrient removal, with A. protothecoides showing a 46.6% increase in ammonium removal and a 44.8% increase in phosphate removal with antibiotics. Additionally, antioxidant activities remained stable, except for a notable increase in peroxidase activity for A. protothecoides and T. obliquus. The study confirms efficient antibiotic removal and stimulatory responses in the three algal strains, indicating their potential for wastewater treatment and combating antimicrobial resistance.

Efficient degradation of methylene blue and ciprofloxacin compounds using heteroanionic titanium oxycarbide photocatalyst and its correlation with their dielectric properties

In recent times, semiconductor-based photocatalysts have emerged as a promising solution for remediating water pollutants. This study contributes to this field by successfully preparing a heteroanionic titanium oxycarbide photocatalyst, denoted as TiO0.5C0.5 (TiOC), through a solid-state reaction. The structural, morphological, optical, vibrational, and chemical bonding properties of TiOC were thoroughly characterized using XRD, TEM, SEM-EDS, UV–Vis DRS, FT-IR, and XPS. The photocatalytic activity of TiOC was evaluated by degrading methylene blue (MB) and ciprofloxacin (CP) under visible light (VL) irradiation in different water sources (deionized, domestic tap, and seawater). Notably, TiOC achieved significant degradation efficiencies of 79 % for MB and 82 % for CP within 180 minutes under VL in deionized water. However, its efficiencies were lower in tap water (65 % for MB, 72 % for CP) and seawater (57 % for MB, 56 % for CP) due to the presence of interfering substances (inorganic ions, radical scavengers), varying initial pH, and salinity. Additionally, dielectric permittivity measurements of TiOC at room temperature revealed a high dielectric constant (ε' ≈ 179), facilitating efficient exciton separation. Its high loss tangent (ε'' ≈ 10) is attributed to improved conductivity, enabling faster charge-carrier transfer kinetics, which contributes to the enhanced removal of MB and CP. Overall, the enhanced removal efficacy of MB and CP using TiOC is attributed to the synergistic effects of enhanced VL absorption, faster charge transfer kinetics, improved exciton separation, and a favorable pH environment.

The role of chitosan in promoting the catalytic activity of bismuth ferrite as peroxymonosulfate activator for antibiotics removal

Chitosan possesses electron-rich amino (−NH2) and hydroxyl (-OH) moieties which can anchor with transition metal ions during synthesis. Herein, chitosan was employed as an additive to prepare bismuth ferrite (BFO) via hydrothermal approach. The characterization studies revealed that adding chitosan during BFO synthesis leads to the creation of more oxygen vacancies. The performance of chitosan modified BFO (CMB) was evaluated as peroxymonosulfate (PMS) activator for ciprofloxacin (CIP) removal. Apparently, the addition of 10 wt% chitosan during BFO synthesis (CMB-10) resulted in 1.7 times increase of performance compared to the pristine BFO. Increasing the catalyst loading and PMS dosage resulted in positive effect with 5.7 and 1.9 times rate enhancement, respectively. The CMB-10 exhibited tolerance against pH variation, water matrix, and interfering species. The scavenging experiments indicated that singlet oxygen (1O2), superoxide radicals (O2•-) and sulfate radicals (SO4•-) played a major role in CIP degradation. These reactive oxygen species were generated from PMS activation via Fe3+/Fe2+ and Bi5+/Bi3+ coupling, and oxygen vacancies on the catalyst surface. The CIP degradation pathways were also elucidated based on the detected CIP intermediates. Overall, this study provides insights into the use of chitosan to prepare sustainable materials for pollutants removal via PMS activation.

Valorization of sponge iron industrial waste into iron-modified zeolite X for ciprofloxacin removal: a multi-parameter optimization study.

Ciprofloxacin (CIP), a commonly used antibiotic, is frequently detected in water bodies and the natural environment. The profound health consequences of CIP have led to growing attention focusing on environmental concerns. Adsorption is highly preferred because of its adaptability and remarkable efficiency in removing CIP. Therefore, the current work focuses on synthesizing an eco-friendly and economical adsorbent for removing CIP. The work aims to remove CIP using zeolite X (ZX), synthesized from dolochar, and subsequently modified ZX into iron-modified zeolite X (FeZX) via ion exchange. The synthesized FeZX had a crystallinity of 82.701%, an average pore size of 5.917 nm, a micropore volume of 0.298 cc/g, a micropore area of 451.807 m2/g, and a total surface area of 478.521 m2/g. The effect of parameters such as initial CIPconcentration, pH, contact period, adsorbent dosage, and iron dosage was analyzed in the batch adsorption studies of CIP using ZX and FeZX. CIP removal of 37.786% was achieved using ZX; hence, the adsorption parameters were optimized to maximize the CIP removal using response surface methodology (RSM), specifically Box-Behnken Design (BBD) using FeZX. Maximum removal of 97.974% was achieved under optimum conditions of 8.06 pH, contact period of 59.422 min, CIP concentration of 17.117 mg/L, and adsorbent dosage of 0.478 g/L. Freundlich isotherm and pseudo-second-order kinetic models werethe most accurate representations of the experimental data. The findings indicatethe significance of using this iron-modified mesoporous zeolite as an adsorbent for efficiently treating CIP wastewater.

β-cyclodextrin-modified cobalt oxide as a heterogeneous catalyst for efficient peroxymonosulfate activation towards the degradation of Ciprofloxacin: Performance and degradation pathways

In this study, β-cyclodextrin-modified cobalt oxide (Co3O4@β-CD) composites were developed through hydrothermal processes and employed for heterogeneous activation of peroxymonosulfate (PMS) for the removal of ciprofloxacin (CIP) antibiotics. The results revealed that the degradation of CIP by Co3O4@β-CD/PMS was 99.13 %, which was significantly higher than the degradation of CIP by Co3O4/PMS (79.06 %) in a 25-minute period under optimal conditions ([Co3O4@β-CD] = 0.25 g/L, [PMS] = 0.25 mM, pH=7.0). The enhanced degradation of CIP contributed to the greater surface area (162.84 m2/g) of the Co3O4@β-CD to the Co3O4 (121.47 m2/g). Besides, the study assessed the impact of several reaction variables and interrupting anions on the abatement of CIP. A possible degradation procedure for CIP has been established by identifying reaction intermediates. The activation of PMS was achieved by both radical and non-radical routes. Further, Co3O4@β-CD exhibited remarkable stability and maintained its degrading efficiency after five consecutive cycles.