Removal Efficiency Of Ciprofloxacin Research Articles

CuCoFe2O4@AC magnetic nanocomposite as a novel heterogeneous Fenton-like nanocatalyst for Ciprofloxacin degradation from aqueous solutions

CuCoFe2O4@Activated Carbon (AC) was synthesized by a fast, simple, and green microwave-assisted coprecipitation method, and then used as a new heterogeneous magnetic nanocatalyst in Fenton-like reaction for ciprofloxacin (CIP) degradation from aqueous media. CuCoFe2O4@AC was characterized by Field emission scanning electron microscopy (FE-SEM), Energy-Dispersive Spectroscopy (EDS), Mapping, Line scan, Fourier-transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), X-Ray diffraction analysis (XRD), vibrating-sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) techniques. The characterization results showed that the CuCoFe2O4@AC nanocomposite was in the ferrite phase with a mesoporous, uniform, quasi-spherical surface and a particle size of about 25 nm. The total volume of single-point adsorption pores was equal to 0.22 cm3 g−1 and the specific surface area was determined to be 199.54 m2 g−1. This nanocomposite had good thermal stability with high magnetic strength. In the presence of H2O2, the synthesized nanocomposite provided a Fenton-like reaction for CIP removal from aqueous solutions. The investigation of this process showed that neutral pH, 1 g L−1 of the nanocomposite, and 73.5 mM of H2O2 were the optimal conditions for CIP removal with an initial CIP concentration of 20 mg L−1. The maximum removal efficiency of 95.77% was attained after 120 min of contact time under the optimum conditions. The CIP degradation during this Fenton-like process followed a pseudo-first-order kinetic model with rate constants (Kapp) of 0.01 min−1. Finally, the CIP removal efficiency after 5 cycles of recovery and regeneration of CuFe2O4@AC was 87.65%. The excellent performance and high catalytic activity of CuCoFe2O4@AC in Fenton-like reaction for CIP removal make it have potential application foreground in the treatment of pharmaceutical wastewater.

Antibiotic ciprofloxacin removal from aqueous solutions by electrochemically activated persulfate process: Optimization, degradation pathways, and toxicology assessment

Ciprofloxacin (CIP) is a commonly used antibiotic in the fluoroquinolone group and is widely used in medical and veterinary medicine disciplines to treat bacterial infections. When CIP is discharged into the sewage system, it cannot be removed by a conventional wastewater treatment plant because of its recalcitrant characteristics. In this study, boron-doped diamond anode and persulfate were used to degrade CIP in an aquatic solution by creating an electrochemically activated persulfate (EAP) process. Iron was added to the system as a coactivator and the process was called EAP+Fe. The effects of independent variables, including pH, Fe2+, persulfate concentration, and electrolysis time on the system were optimized using the response surface methodology. The results showed that the EAP+Fe process removed 94% of CIP under the following optimum conditions: A pH of 3, persulfate/Fe2+ concentration of 0.4 mmol/L, initial CIP concentration 30 mg/L, and electrolysis time of 12.64 min. CIP removal efficiency was increased from 65.10% to 94.35% by adding Fe2+ as a transition metal. CIP degradation products, 7 pathways, and 78 intermediates of CIP were studied, and three of those intermediates (m/z 298, 498, and 505) were reported. The toxicological analysis based on toxicity estimation software results indicated that some degradation products of CIP were toxic to targeted animals, including fathead minnow, Daphnia magna, Tetrahymena pyriformis, and rats. The optimum operation costs were similar in EAP and EAP+Fe processes, approximately 0.54 €/m3.

High-performance NiO@Fe3O4 magnetic core-shell nanocomposite for catalytic ozonation degradation of pharmaceutical pollution.

Pharmaceuticals that are present in superficial waters and wastewater are becoming an ecological concern. Therefore, it is necessary to provide high-performance methods to limit the harmful ecological effects of these materials to achieve a sustainable environment. In this research, NiO@Fe3O4 nanocomposite was prepared by the co-precipitation method and utilized in the catalytic ozonation process for the degradation of 1-cyclopropyl-6-fluoro-4-oxo-7-piperazin-1-yl-quinoline-3-carboxylic acid (ciprofloxacin antibiotic), for the first time. The influencing parameters in the degradation process were analyzed and optimized via response surface methodology (RSM). The optimal ciprofloxacin removal efficiency (100%) was found at pH = 6.5, using 7.5 mg of the NiO@Fe3O4 nanocatalyst and 0.2 g L-1 h-1 ozone (O3) flow, applied over 20 min. Results showed a significant synergistic effect in the analyzed system, which makes the proposed catalytic ozonation process more efficient than using the catalyst and ozone separately. Also, based on the kinetic analysis data, the catalytic ozonation process followed the pseudo-first-order model. In addition, the nanocatalyst showed high recyclability and stability (88.37%) after five consecutive catalytic ozonation process cycles. In conclusion, the NiO@Fe3O4 nanocatalyst/O3 system can be effectively used for the treatment of pharmaceutical contaminants.

Construction of microwave/PMS combined dual responsive perovskite-MXene system for antibiotic degradation: Synergistic effects of thermal and non-thermal

A series of two-dimensional catalysts (LFCO/Ti3C2-x) were prepared by dispersing perovskite on layered Ti3C2 for microwave-combined PMS catalyzed degradation of ciprofloxacin (CIP). Under the optimal treatment conditions (10% Ti3C2 composite, 1.5 g·L−1 catalyst dosage, 1 mM PMS concentration and initial pH = 7.0), the catalyst achieved 96.49% CIP removal efficiency within 14 min. The addition of Ti3C2 contributed to the granulation and homogeneous dispersion of perovskite, which facilitated charge transfer and generation of active species. The catalyst characterization before and after the reaction and experiments related to the quenching of the active species confirmed that the thermal effect of MW irradiation promoted the generation of ROS. The non-thermal effect of MW enhanced the electron transfer ability of the catalytic system and accelerated the oxidation of metal sites, which indirectly promoted the generation of ROS. Combined with LC-MS and DFT calculations, the degradation pathway and mechanism of CIP were revealed. Meanwhile, the ecotoxicity of CIP intermediates calculated using ecological structure–activity relationship software indicates that they are much less harmful or not toxic. This work opens new perspectives for the application of perovskite-MXene based catalysts in the rapid and efficient catalytic activation of MW combined AOPs for antibiotic degradation.

Stress responses of partial denitrification system under long-term ciprofloxacin exposure in an anaerobic sequencing batch reactor

This study evaluated the stress response of partial denitrification (PD) sludge system under ciprofloxacin (CIP) exposure. The results showed that the nitrite accumulation rate (NAR) decreased from 77.41 % to 28.39 % under CIP stress of 200 µg/L, and after adapting to CIP stress, the NAR of PD system recovered to 61.56 % even the CIP increased to 1000 µg/L. The average COD removal efficiency increased from 69.08 ± 2.01 % to 73.33 ± 2.33 %, and the average removal efficiency of CIP increased from 9.83 % ± 0.71 % in phase II (CIP=50 µg /L) to 30.15 % ± 1.63 % in phase V (CIP=1000 µg /L). Under CIP stress, the protein (PN) in Tightly Bound-extracellular polymeric substances (TB-EPS) increased from 77.60 mg/(g-SS) in phase I to 135.58 mg/(g-SS) in phase Ⅲ (influent CIP=200 µg /L). FTIR revealed that functional groups (CO, C-H, C-O-C) in EPS of PD sludge could bind to CIP to protect microbial cells from damage. The results of principal co-ordinates analysis (PCoA) showed that the addition of CIP had a significant effect on the microbial community structure, CIP exposure led to an increase in biodiversity of PD system. At genus level, Thauera genus abundance decreased, while OLB12 and Denitratisoma genus abundances increased under CIP stress. This was consistent with the result that the conversion of NO3--N to NO2--N was inhibited while NO2--N reduction was promoted. The findings of this study provided insight into the stress-responses of PD system under long-term CIP exposure and provided useful guidance for the risk assessment and control strategy of wastewater treatment plants (WWTPs).

Tween 80 assisted washing ciprofloxacin-contaminated soil, and recycled it using active chlorines

Active chlorines (ACs) can selectively oxidize contaminants with benzene rings to recycle surfactants, which greatly facilitates the resource cycle. This paper firstly utilized Tween 80 to assist in ex-situ washing the ciprofloxacin (CI) contaminated soil, including the solubilization experiment, shake washing and soil column washing, all of which showed that 2 g/L of Tween 80 (TW 80) was the most effective in removing CI. Then electrochemically treated the collected soil washing effluent (SWE) at 10 V with an electrolyte of 20 mM NaCl + 10 mM Na2SO4; Pre-experiments screened the range of electrode spacing, pH and temperature, based on which an orthogonal design Table L9 (34) was designed. Visual analysis and ANOVA were performed on the ciprofloxacin removal efficiency and Tween 80 retention efficiency during the orthogonal experiments in 9 groups, and the results showed that CI was usually degraded within 30 min, and 50% of TW 80 was still present at the end of the experiment, and there was no significant effect of all three factors. LC-MS demonstrated that CI was mainly degraded synergistically by ·OH and ACs, and ·OH effectively reduced the biotoxicity of the SWE, so the mixed electrolyte may be more suitable for the electrochemical recycling system of ACs. This paper conducted the washing remediation study of CI-contaminated soil for the first time, and applied the theory of selective oxidation by ACs on benzene ring to treat the SWE, which provides a new treatment idea for antibiotic-contaminated soil.

Sunlight-driven photocatalytic degradation of ciprofloxacin and organic dyes by biosynthesized rGO–ZrO2 nanocomposites

Aquatic ecology has been greatly threatened by the discharge of effluents of textile and antibiotic industries into natural waters. Herein, an efficient and easily recycled reduced graphene oxide/zirconium oxide nanocomposite has been synthesized using banana peel extract (abbreviated as rGO-ZrO2 in this work). The X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), UV-visible diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy were used to analyze the synthesized material. The as-prepared rGO-ZrO2 nanocomposite was employed as a photocatalyst for the decomposition of rhodamine blue (RhB) and crystal violet (CV) dyes, and ciprofloxacin (CIP) antibiotic by illumination with direct sunlight. The RhB and CV were degraded to maximum extent of around 86 and 90%, respectively, over the rGO-ZrO2 nanocomposite after exposure to direct sunlight for 120min. On the other hand, the degradation of CIP was approximately 93.1% over the rGO-ZrO2 nanocomposite in 240min under same experimental conditions. Further studies were performed regarding the role of parameters like pH, catalyst dose, and scavengers, in order to understand the superiority of rGO-ZrO2 nanocomposite in degrading organic pollutants. Moreover, the intermediate products and plausible CIP degradation mechanisms were examined using liquid chromatography-mass spectrometry (LC-MS). Moreover, the catalyst was easily separated from the solution and demonstrated good stability and reusability. The RhB, CV, and CIP removal efficiency were 80%, 83%, and 88%, respectively, after five cycles.

Algae-mediated bioremediation of ciprofloxacin through a symbiotic microalgae-bacteria consortium

The ciprofloxacin treating via microalga and its microalgae-bacteria consortium was investigated for discussing the potential application of microalgae-mediated bioremediation. As results, the maximum removal efficiency of ciprofloxacin by pure microalgae and the consortium was 87.5 ± 3.5 % (5 mg/L) and 96.1 ± 0.07 % (40 mg/L), respectively. The consortium enhanced the degradation rate to 0.81 d−1 compared with the pure microalgae (0.27 d−1). To reveal the symbiotic mechanism, extracellular polymeric substances, pigments contents, antioxidant enzymes and symbiotic bacterial community were analyzed. The malondialdehyde content in the pure microalgae (1622.6 ± 38.7 nmol/mg protein) was higher than that in the consortium (298.34 ± 2.4 nmol/mg protein), and there were obvious chlorophyll b accumulations (approximately 90 %) in consortium. In addition, the symbiotic bacteria had a positive effect on microalgal secretion of fulvic acid-type components. As mechanism, symbiotic bacteria improved ciprofloxacin biodegradation by reducing cell damage and secreting fulvic acid. The presence of Phycisphaeraceae and Rhizobiaceae, nitrogen fixation bacteria, in the consortium suggest that improvement of ciprofloxacin biodegradation might be associated with nitrogen co-metabolism as well. Collectively, this work elucidates the mechanism of enhancing elimination of ciprofloxacin via microalgae-bacteria consortium and accelerates development of microalgae-mediated aquaculture tailwater bioremediation.

Catalytic Degradation of Ciprofloxacin in Aqueous Solution by Peroxymonosulfate Activated with a Magnetic CuFe2O4@Biochar Composite

A magnetic copper ferrite and biochar composite (CuFe2O4@BC) catalyst was prepared by an improved sol-gel calcination method and initially used for the removal of antibiotics ciprofloxacin (CIP) by activated peroxymonosulfate (PMS). Using CuFe2O4@BC as the activator, 97.8% CIP removal efficiency could be achieved in 30 min. After a continuous degradation cycle, CuFe2O4@BC catalyst still exhibited great stability and repeatability and could also be quickly recovered by an external magnetic field. Meanwhile, the CuFe2O4@BC/PMS system presented good stability for metal ion leaching, which was far less than the leaching of metal ions in the CuFe2O4/PMS system. Moreover, the effects of various influencing factors, such as initial solution pH, activator loading, PMS dosage, reaction temperature, humic acid (HA), and the inorganic anions were explored. The quenching experiments and the electron paramagnetic resonance (EPR) analysis manifested that hydroxyl radical (•OH), sulfate radical (SO4•-), superoxide radical (O2•-), and singlet oxygen (1O2) were generated in the CuFe2O4@BC/PMS system, while 1O2 and O2•- are mainly involved in the degradation process. The synergistic effect between CuFe2O4 and BC enhanced the structural stability and electrical conductivity of the material, which promoted the bonding between the catalyst and PMS, resulting in the enhanced catalytic activity of CuFe2O4@BC. This indicates that CuFe2O4@BC activating PMS is a promising remediation technique for CIP-contaminated water.

Evaluation of Sono-photocatalytic Removal of Ciprofloxacin Antibiotic Using Magnesium Oxide Nanoparticles from Aqueous Solutions

Objectives: The entry of antibiotics into surface and groundwater will cause problems in the environment. This study aimed to investigate the removal efficiency of ciprofloxacin (CFX) from aqueous solutions using the sonophotocatalytic process of Magnesium Oxide Nanoparticles (MgO). Materials and Methods: This study is an experimental-laboratory study performed in a reactor with a discontinuous system. In this study, the effect of parameters such as solution pH, MgO dose, reaction time in two processes, photocatalyst and sonocatalyst, initial concentration of antibiotic and the power of UV lamps in the photocatalytic reactor at ultrasonic frequencies of 35 and 130 kHz on the reduction of CFX in aqueous solution was investigated. Results: The results showed that the process of photosonocatalysis with MgO can effectively lead to the removal of the antibiotic CFX. In the process of using a photosonocatalyst with a pH of 7 and ultrasonic waves with a frequency of 35 kHz and an optimal time of 30 min, 0.3 g/L of MgO, CFX concentration of 150 mg/l, UV lamp with a power of 30 watts and the optimal irradiation time of 60 min was obtained as the optimal variables in the removal of CFX antibiotic. Conclusion: The results showed that the photosonocatalytic process with the help of MgO is an effective and efficient method to remove the CFX antibiotic from aqueous solutions.

Green Synthesis of Fe–Cu Bimetallic Supported on Alginate-Limestone Nanocomposite for the Removal of Drugs from Contaminated Water

In this study Fe-Cu supported on Alginate-limestone (Fe-Cu/Alg-LS) was prepared. The increase in surface area was the main motivation for the synthesis of ternary composites. Scanning electronic microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) were used to examine the surface morphology, particle size, percentage of crystallinity, and elemental content of the resultant composite. Fe-Cu/Alg-LS was used as an adsorbent for the removal of drugs such as ciprofloxacin (CIP) and levofloxacin (LEV)from contaminated medium. The adsorption parameters were computed using kinetic and isotherm models. The maximum removal efficiency of CIP (20 ppm) and LEV (10 ppm) was found to be 97.3% and 100%, respectively. The optimal conditions were pH 6 and 7 for CIP and LEV, optimum contact time 45, 40 min for CIP and LEV, and temperature of 303 K. The pseudo-second-order model, which confirmed the chemisorption properties of the process, was the most appropriate kinetic model among the ones used, and the Langmuir model, which was the most appropriate isotherm model. Moreover, the parameters of thermodynamics were also assessed. The results imply that the synthesized nanocomposites can be used to remove hazard materials from aqueous solutions.

Efficient degradation of ciprofloxacin by activated peroxymonosulfate using OV-rich NiCo4-LDH: Insights into radical production pathway and catalytic mechanism

In this study, the NiCo4-LDH with abundant surface oxygen vacancies (SOVs) was synthesized by a simple solvent thermal method, and was used to activate peroxymonosulfate (PMS) through heterogenous catalysis for ciprofloxacin (CIP) degradation. The OV-rich NiCo4-LDH/PMS system exhibited excellent CIP removal efficiency and rapid kinetics, as 95.0 % of the CIP was degraded within 10 min and the COD removal rate was 71.2 %. SO4•−, •OH, O2•− and 1O2 were involved in the degradation of CIP, with O2•− contributing the most, followed by SO4•−, •OH and 1O2. Ethanol, as solvent, could modulate the intrinsic electron properties and produce abundant OVs on the surface of NiCo4-LDH, which enhanced the generation of O2•−. This study shed new light on the skillful design and application of heterogeneous catalysts for environmental remediation.

The influence of B heteroatom concentrations on the physiochemical properties of N, B-co-doped biochar for peroxymonosulfate activation in ciprofloxacin removal

N, B-co-doped biochars with varying boric acid (BA):urea mass ratio were prepared by two-step calcination of sawdust (NB-BC-x, where x = 1, 2, and 3 corresponds to the BA:urea mass ratio of 0.025:1, 0.05:1, and 0.1:1, respectively) and characterized. Generally, B doping prior to N doping can improve N doping because the presence of oxidized B during N doping can interact with NH3, facilitating N doping. The performance of NB-BCs in PMS activation for ciprofloxacin (CIP) removal was evaluated and it was found that the kapp increased in the order of: N-BC (0.010 min−1) < B-BC (0.016 min−1) < NB-BC-2 (0.031 min−1) < NB-BC-3 (0.039 min−1) < NB-BC-1 (0.053 min−1). Due to its large specific surface area and synergistic interaction between N and B moieties, NB-BC-1 presented the best PMS activator, achieving CIP removal of ∼45 and ∼80 % by adsorption and degradation in 60 min, respectively. Further performance study using NB-BC-1 revealed that the kapp increased with increasing catalyst loading and PMS dosage. Meanwhile, higher pH can reduce the CIP removal efficiency due to the electrostatic repulsion between NB-BC-1 and PMS. It was also demonstrated that NB-BC-1 can be reused and regenerated after deactivation using thermal treatment at 500 °C. From the chemical scavengers and electrochemical studies, it can be deduced that NB-BC-1 activates PMS through both radical and nonradical pathways. Lastly, the degradation pathway of CIP was also proposed by identifying the degradation intermediates and their toxicity were accessed. Overall, this study showed that NB-BC-1 can potentially be used as a PMS activator for wastewater treatment.

Photocatalytic Degradation of Ciprofloxacin by UV Light Using N-Doped TiO2 in Suspension and Coated Forms

The presence of organic compounds such as ciprofloxacin in untreated pharmaceutical wastewater often poses a serious health risk to human and aquatic life when discharged into water bodies. One of the most effective means of removing ciprofloxacin from wastewater is photocatalytic degradation. However, the synthesis of an effective photocatalyst that can degrade the organic pollutant in the wastewater is often a challenge. Hence, this study focuses on the synthesis and application of nitrogen-doped TiO2 (N-TiO2) in suspension and coated forms for the photocatalytic degradation of ciprofloxacin in wastewater by applying UV-light irradiation. The nitrogen-doped TiO2 photocatalyst was prepared by a co-precipitation process and characterized using energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The effects of the initial concentration of the ciprofloxacin (6, 12, 18, or 30 ppm), pH (3, 5, 7, or 9), and flow rate (0.4, 0.8, 0.95, or 1.5 L/min) on the degradation of the ciprofloxacin over the N-TiO2 were investigated. The results showed that the removal efficiency of ciprofloxacin was enhanced by increasing the initial ciprofloxacin concentration, while it was decreased with the increase in the feed flow rate. The best operating conditions were obtained using an initial ciprofloxacin concentration of 30 ppm, pH of 5, and feed flow rate of 0.4 L/min. Under these operating conditions, removal efficiencies of 87.87% and 93.6% were obtained for net TiO2 and N-TiO2 of 5 wt% in suspension form, respectively, while 94.5% ciprofloxacin removal efficiency was obtained using coated 5 wt% N-TiO2 after 2 h of photocatalytic degradation. Based on the response surface optimization strategy, a quadratic model was suggested to obtain mathematical expressions to predict the ciprofloxacin removal efficiency under various studied operational parameters.

Magnetic-Transition-Metal Oxides Modified Pollen-Derived Porous Carbon for Enhanced Absorption Performance

In our work, the transition-metal-oxide precursor (TMO@BC, M = Fe, Co, Ni) has been loaded on the pollen carbon by the hydrothermal method and annealed at different temperatures to generate a composite material of metal oxide and pollen carbon in this study, which can effectively prevent agglomeration caused by a small size and magnetism. The XRD patterns of the samples showed that the as-synthesized metal oxides were γ-Fe2O3, CoO, and NiO. In the 20 mg/L methyl orange adsorption experiment, the adsorption amount of CoO@C at 500 ℃ reached 19.32 mg/g and the removal rate was 96.61%. Therefore, CoO@C was selected for the adsorption correlation-model-fitting analysis, which was in line with the secondary reaction. The pseudo-second-order kinetic model (R2: 0.9683-0.9964), the intraparticle diffusion model, and the Freundlich adsorption isotherm model indicated that the adsorption process was the result of both physical and chemical adsorptions, and the judgment was based on the electrostatic action. The adsorption and removal efficiency of ciprofloxacin (CIP) by changing the pH of the reaction was about 80%, so the electrostatic attraction worked, but not the main factor. Recovered by an external magnetic field, the three-time recycling efficiency was still maintained at more than 80%. This novel biomass-derived magnetic porous carbon material embedded with transition-metal-oxide nanoparticles is highly promising for many applications, especially in the field of environmental remediation.

Dual redox cycles of Mn(Ⅱ)/Mn(III) and Mn(III)/Mn(IV) on porous Mn/N co-doped biochar surfaces for promoting peroxymonosulfate activation and ciprofloxacin degradation

Mn and N co-doped biochar (Mn-N-TS) was prepared as an effective catalyst to activate peroxymonosulfate (PMS) for ciprofloxacin (CIP) degradation. As opposed to Mn-TS and N-TS, Mn-N-TS had more active sites containing N and Mn, as well as a greater specific surface area (923.733 m2 g−1). The Mn-N-TS exhibited excellent PMS activation ability. In the Mn-N-TS/PMS system, the CIP removal efficiency was 91.9% in 120 min. Mn and N co-doping could accelerate electron transfer between CIP and PMS molecules. Simultaneously, defect sites, graphitic N, pyridinic N, C═O groups, and Mn(II)/Mn(III)/Mn(IV) redox cycles acted as active sites to activate PMS and generate free radicals (OH, SO4− and 1O2). Furthermore, the Mn-N-TS/PMS system could effectively degrade CIP in a wide pH range, background substances, and actual water. Finally, a probable mechanism of PMS activation by Mn-N-TS was proposed. In conclusion, this work gave a novel direction for the rational design of Mn and N co-doped biochar.

Quaternary composite of CdS/g-C3N4/rGO/CMC as a susceptible visible-light photocatalyst for effective abatement of ciprofloxacin: Optimization and modeling of the process by RSM and ANN

Ciprofloxacin (CIP) is an antibacterial agent extensively used to treat acute infections. This antibiotic is frequently excreted in an incompletely metabolized form and ultimately enters the environment through wastewater. This study aims to design and optimize an efficacious photocatalytic process to abate CIP from aqueous media. To this end, a novel carboxymethyl cellulose (CMC) based nanocomposite containing CdS, g-C3N4, and rGO (CdS/g-C3N4/rGO/CMC) was synthesized via a hydrothermal route and used as a visible-light-driven photocatalyst to degrade CIP. The photocatalytic process was designed and optimized through two effective approaches: response surface methodology (RSM) and artificial neural networks (ANNs). The removal efficiency of CIP and TOC achived 81.93% and 68.87%, respectively, under RSM-based optimal conditions (8 mg L−1 CIP, 0.6 g L−1 catalyst, at pH= 6.1 within 35 min). Based on the ANN analysis, the relative importance of process-influencing parameters was: catalyst dosage (34%), pH (30%), irradiation time (26%), and CIP initial concentration (10%). Evaluation of the process mechanism revealed that the principal active species in the photocatalytic degradation of CIP were hydroxyl radicals and holes. The kinetic studies demonstrated that the photocatalytic degradation of CIP through CdS/g-C3N4/rGO/CMC followed the pseudo-first-order model with a rate constant of 0.0469 min−1. Furthermore, the catalyst’s reusability was confirmed under optimal conditions. Consequently, the synthesized nanobiocomposite could render a prominent photocatalytic activity to remove stubborn pollutants from wastewater.

Enhanced Degradation of Ciprofloxacin in Floating Treatment Wetlands Augmented with Bacterial Cells Immobilized on Iron Oxide Nanoparticles

Antibiotic contamination of water is an emerging global issue with severe implications for both public health and the environment. Ciprofloxacin (CIP) is a synthetic fluoroquinolone antibiotic, which is broadly used in human and veterinary medicines around the world to treat various bacterial infections. The presence of CIP in the aquatic environment poses serious health problems to human beings and other living entities. Floating treatment wetland (FTW) is a low-cost and eco-friendly wastewater remediation technology. In the current study, the Canna indica. (Indian shot) was vegetated in a floatable mat to develop FTWs. A consortium of three bacterial strains, Acinetobacter lwoffii ACRH76, Bacillus pumulis C2A1, and Acinetobacter sp. HN3, was immobilized on iron oxide nanoparticles (Fe3O4-NPs) and augmented in the FTWs for the remediation of CIP-contaminated (100 mg/L) water. The augmentation of bacteria (immobilized or free) in the FTWs significantly enhanced the removal of CIP from water. The maximum reduction in CIP (98%), chemical oxygen demand (COD; 90%), biochemical oxygen demand (BOD; 93%) and total organic carbon (TOC; 95%) was observed in FTWs that had Fe3O4-NP supported bacteria. This study reveals that FTWs have a great potential to remove the CIP from contaminated water, albeit its CIP removal efficiency was substantially enhanced by augmentation with Fe3O4-NPs supported bacteria.

Synergistically enhanced activation of peroxymonosulfate by Fe3O4@ZSM-5 catalysts for ciprofloxacin degradation: Performance, kinetics and mechanism insight

Exploring an environmentally friendly and highly activation catalysts in the advanced oxidation processes (AOPs) basing on sulfate radicals (SO4−•) has shown great importance for the remediation of refractory contaminants. Herein, Fe3O4-wrapped ZSM-5 (Fe3O4@ZSM-5) was constructed as heterogeneous catalyst to remove ciprofloxacin (CIP) via peroxymonosulfate (PMS) activation, in which performance, kinetics and mechanism insight were investigated in depth. The removal efficiency of CIP reached 90 % by Fe3O4@ZSM-5 catalysts within 100 min reaction when the initial pH was 3.0. During the reaction, SO4−• and HO• were proved to be coexisted in reaction system and SO4−• played a critical role in CIP degradation according to the radical quenching experiments and electron paramagnetic resonance (EPR) measurements. Based on the catalyst characterization and Langmuir-Hinshelwood adsorption kinetics analysis, the synthesis of Fe3O4 nanoparticles (NPs) and ZSM-5 accelerated the dispersion process and enhanced adsorption ability of Fe3O4 NPs, which further promoted the local concentration of CIP and PMS on the surface. In addition, the cycling experiments and metal leaching tests demonstrated that Fe3O4@ZSM-5 catalysts were stable and could be conveniently reused by magnetic separation. In addition, the impacts of coexisting irons (Cl−, SO42−, NO3−, HCO3−) confirmed that Fe3O4@ZSM-5 was still effective in real water. This study demonstrated the promising prospect of Fe3O4@ZSM-5/PMS system in the application of degradation refractory organic pollutants.

Optimisation of ciprofloxacin removal by using polymer inclusion membrane and its multivariate analysis with half‐fractional factorial design

AbstractBACKGROUNDIn this study, the use of polymer inclusion membranes (PIMs) to attenuate the recalcitrant contaminant of ciprofloxacin (CIP) in an aquatic system is presented. Poly(vinyl)chloride (PVC) was used as the base polymer, bis−2‐(Ethylhexyl) phosphate (B2EHP) as the carrier, and dioctyl phthalate (DOP) as the plasticizer. Optimisation of the experiment was conducted using multivariate analysis of half‐fractional factorial design, focusing on parameters like pH of the source solution, the source solution's concentration, carrier composition, the concentration of the receiving solution, and extraction time.RESULTSIt was found that PIMs with the composition of PVC 45%: B2EHP 25%: DOP 30% were the best suited for this purpose. The optimal removal efficiency of CIP was ˃99% at pH 6, 90% at pH 12, and 85% removal at neutral pH (7). After various optimisation steps, the method was applied to actual environmental wastewater and river samples with an average percentage removal efficiency of ˃97%.CONCLUSIONThis study has successfully demonstrated the feasibility of using PIMs for the removal of CIP antibiotics. Hence, it may be considered a practical treatment approach for other pharmaceutical residues in the aquatic system. © 2022 Society of Chemical Industry (SCI).