Initial Ciprofloxacin Research Articles

Antibiotics pollutants in agricultural soil: Kinetic, sorption, and thermodynamic of ciprofloxacin

The entry of antibiotics, as pollutants, into the environment has created great concerns. Environmental dynamics of antibiotics based on soil chemical properties need to be a better understanding of their chemical behavior. This research is focused on studying the adsorption behavior and kinetic mechanisms of ciprofloxacin (CIP) in an agricultural soil. For this purpose, a batch experiment was conducted at different times (5 min–24 h), and using initial concentrations of CIP (0–1 mmol L−1) in the soil. The adsorption processes as affected by pH and ionic strength were assessed based on the modeling with response surface methodology (RSM). According to the results, the sorption equilibrium was found within 240 min, and the pseudo second-order model was the best for describing the data. Increasing the initial CIP concentration increased CIP adsorption, but increases in ionic strength and pH had an inverse effect. Based on RSM modeling, the CIP adsorption was 7.31 and 7.03 (mg g−1) in the presence of NaCl and CaCl2 electrolytes, respectively, in the optimized conditions (pH 6.5 and ionic strength 0.01 mol L−1). The spontaneous nature of CIP adsorption was determined based on thermodynamic calculations (ΔG° = −10.8 to −12.4 kJ mol−1). The interaction of pH and ionic strength was described with the quadratic model. The obtained results contribute to understanding the CIP fate in the soil environment and facilitate decisions regarding entry and controlling soil contamination due to this antibiotic.

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.

Red mud supported on rice husk biochar as sono-photo-Fenton catalysts for degradation of ciprofloxacin in water

To develop efficient methods to reuse red mud and rice husk waste to remove ciprofloxacin (CIP) in water, a simple and efficient Fenton catalyst based on red mud/rice husk biochar composite (RMR) was prepared using ultrasonic-assisted impregnation method. The effects of initial solution pH, initial CIP concentration, contact time, and catalyst dose on the removal of CIP in water were studied. The results showed that at pH 3, RMR dose of 1.0 g/L, CIP concentration of 20 mg/L, treatment time of 180 min, and temperature of 50 °C, the degradation efficiency was the highest at 75.97 % for sono-Fenton (SF) and 95.65 % for sono-photo-Fenton (SPF) with in situ generation of H2O2 during processes, indicating RMR has a great potential application in the treatment of organic pollution in actual wastewater. Other factors such as the co-existing anions (NO3–, SO42−, Cl−) or water matrices and other antibiotics were also investigated to prove the good removal of CIP by RMR for practical applications.

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.

Ciprofloxacin adsorption onto CNT loaded Pumice: Adsorption Modelling, kinetics, equilibriums and reusability studies

A novel CNT-derived Pumice adsorbent (P-CNT3) was successfully synthesized as an efficient adsorbent for Ciprofloxacin (CIP) removal from aqueous solutions. In present study, P-CNT3 composite synthesized by hydrothermal technique was loaded with multiwalled carbon nanotube (CNT) using sonification to remove CIP antibiotic. P-CNT3 composite were characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. Adsorption performance was studied by adjusting the pH, contact time, initial CIP concentration, temperature and adsorbent dosage in a batch reactor to obtain the maximum adsorption capacity (qm). The maximum adsorption capacity (qm) was achieved in 240 min at pH ≤ 5).The adsorption process of P-CNT3 followed the pseudo-first-order kinetic model (R2 = 0.989) and sips isotherm model (R2 = 0.991), and qm to adsorb CIP was 28.6 mg/g. The illustrated adsorption mechanism shows that hydrophobic interactions, electrostatic and non-electrostatic interactions, suggests CIP adsorption. Over the temperature range of 298–318 K, the thermodynamic parameters ΔG°, ΔS° and ΔH° were calculated. The adsorption reactions were shown to be spontaneous and endothermic. Furthermore, activation energy suggested a physisorption mechanism for P-CNT3. In addition, regeneration study shows that the P-CNT3 can be reused five times with excellent results in CIP adsorption. Based on these findings, P-CNT3 can be considered a feasible low-cost adsorbent for CIP removal. Hence, the prepared P-CNT3 composite can be used as an inexpensive and a promising adsorbent for the removal of other pharmaceutical compounds.

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.

Synthesis of Ag/ZnO/BiOCl Composite Material and Its Photodegradation Performance on Ciprofloxacin

This study focuses on synthesizing a composite material of Ag/ZnO/BiOCl using Ag, ZnO, and BiOCl as raw materials. The material was prepared by loading Ag and BiOCl onto ZnO nanofilms, aiming to enhance the photocatalytic degradation of ciprofloxacin (CIP). Optimization of the photocatalytic degradation process through single-factor experiments revealed that under conditions of an initial CIP pH of 9, an Ag/ZnO/BiOCl dosage of 1 g/L, and an initial CIP concentration of 5 mg/L the conversion efficiency of CIP reached 98.79% after 150 min of exposure to a 250 W xenon lamp simulating sunlight. Furthermore, the composite material maintained a conversion efficiency of 86.17% for CIP even after five cycles of reuse, demonstrating its excellent stability. The optical properties, elemental composition, valence state, crystallinity, and morphology of the samples were analyzed using techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), UV–visible diffuse reflectance spectroscopy (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results indicate that the introduction of Ag expanded the light response range of ZnO, while the addition of BiOCl improved the separation efficiency of electron–hole pairs in the composite nanomaterial. The photocatalytic mechanism was further elucidated through radical scavenging experiments, confirming that ·OH and h+ are the main active species in the degradation process.

Photocatalytic degradation of ciprofloxacin from water with waste polystyrene and TiO2 composites

Ciprofloxacin (CIP) is one of the widely used antibiotics with a broad antimicrobial spectrum in the fluoroquinolone type. Its concentration in water bodies has increased over the years due to its frequent use. Since ciprofloxacin in the aquatic ecosystem adversely affects human health as well as other organisms, it must be removed from wastewater.The aim of this study was to develop Polystyrene (PS) and Titanium dioxide (TiO2) composites that can be used as catalysts in CIP removal by photocatalytic process. Waste PS (obtained from disposable cutlery) was used in the synthesis of these composites. In this study, PS-TiO2 composites with different PS content (C20, C50, C80; the numbers in the names indicate the PS percentage in the composite by weight) were synthesized. This is important in terms of the use of one waste in the removal of another waste.This process was optimized using Box-Behnken design, one of the response surface method. Parameters such as the amount of polymer in the composite, pH and initial CIP concentration were studied and their effects on CIP removal were found. The validity and adequacy of the selected model were evaluated according to the relevant statistical data. These are R2 = 0.9751, adjusted R2 = 0.9565, the model's p-value <0.05 and the lack of fit-value 0.246. Optimum conditions for CIP removal were obtained when the C50 was used, with a pH value of 3 and an initial CIP concentration of 5 mg/L.In the process carried out under these conditions, the CIP removal was found to be 95.01 % at the end of 180 min. This value was predicted as 94.37 % in the model. According to these results, C50 composite synthesized with waste PS can be used effectively for CIP removal.

Electrochemical degradation of ciprofloxacin from water: Modeling and prediction using ANN and LSSVM

Ciprofloxacin is a widely used antibiotic that is also a persistent contamination that causes major health and environmental risks. This study investigated the electrochemical removal of ciprofloxacin using a boron-doped diamond anode and a non-supportive electrode to get an accurate understanding of the anode's performance. The effects of current density, initial ciprofloxacin concentration, time, pH, and electrolyte concentration on the removal efficiency of ciprofloxacin were investigated. Additionally, ANN and LSSVM models were used to predict ciprofloxacin removal. The results showed that the BDD anode was effective in removing ciprofloxacin from water, with complete removal of 10 mg L−1 CIP in less than 45 min with electrolyte concentration of 25 g L−1, a current density of 20 mA cm−2, and a pH value of 3. The removal efficiency was found to increase with increasing current density and time because it increases the concentration of active species. The removal efficiency was also found to be higher at acidic pH values and higher electrolyte concentrations. The ANN model was found to be more accurate in predicting ciprofloxacin removal than the LSSVM model, with an R2 of 0.9982 and an AARE% of 2.68%, compared to R2 of 0.9978 and an AARE% of 3.85%. The models were validated using a new set of data, and the results showed that the ANN model was able to accurately predict ciprofloxacin removal under a variety of conditions.

Ciprofloxacin antibiotic removal from aqueous solutions by ZnO nanoparticles coated on ACA: modeling and optimization.

Antibiotics are one of the most widely used drug groups. The presence of antibiotics in urban water sources and sewage creates many environmental and medical risks for humans and other living organisms. In this study, the potential of zinc oxide (ZnO) coated on almond shell activated carbon (ACA-ZnO) in removing ciprofloxacin (CIP) from aqueous solutions was investigated. Almond shell was used to make activated carbon. Zinc oxide nanoparticles were prepared by the sol-gel method, and finally, ZnO nanoparticles were bonded to activated carbon. The effect of independent parameters pH, contact time, adsorbent dose, and initial CIP concentration on CIP removal efficiency using ACA-ZnO was investigated by response surface methodology. Optimal removal was obtained at pH = 5.4, CIP initial concentration = 7.4 mg/L, adsorbent dose = 0.82 g/L, and reaction time = 67.3 min. This study followed a quadratic model (R2 = 0.958). The best model of adsorption isotherm fits with the Freundlich model (R2 = 0.9972) and the maximum capacity was 251.42 mg/g adsorption kinetics, and pseudo-second-order kinetic model (R2 = 0.959). The results of this study showed that ACA-ZnO as an adsorbent is very efficient, without environmental side effect and cost-benefit.

Activation of peroxymonosulfate for ciprofloxacin degradation by a novel oxygen-deficient CoTiO3/TiO2NTs/Ti composite catalytic membrane:Electron transfer pathway and underlying mechanism

The technique of activating peroxymonosulfate (PMS) by enriching oxygen vacancies (Vo) in heterogeneous catalysts has gained extensive attentions in the removal of emerging contaminants, e.g., antibiotics from wastewater. In this study, a Vo-CoTiO3/TiO2NTs/Ti (Vo-CTNs) catalytic membrane with rich oxygen vacancies was prepared and employed for the activation of PMS in degrading ciprofloxacin (CIP) in a continuous flow reactor. The averaged degradation efficiency of CIP in the Vo-CTNs/PMS system could reach 97.3 %, significantly higher than that in the CoTiO3/TiO2NTs/Ti (CTNs) system (91.1 %). Quenching experiments and electron paramagnetic resonance analysis collectively confirmed the presence of •OH, SO4•−, O2•− and 1O2 during the CIP degradation process. The results of the electrochemical experiments demonstrated that in the presence of oxygen vacancies, the mutual conversion between Co2+ and Co3+ was facilitated, resulting in a lower transfer resistance. At an initial CIP concentration of 10 mg/L and a membrane flux of 600 LMH, the degradation efficiency and mineralization rate of CIP could reach 95.2 % and 51.1 % after 12 h of operation, respectively. Meanwhile, limited leaching of cobalt ions (52 μg/L) from the catalytic membrane was observed during treatment. Theoretical calculations revealed that Vo engineering can modulate the surface electronic states, thereby enhancing binding energy and electron transfer for PMS activation. The degradation of CIP is mainly achieved through the ring opening reactions in the piperazine, quinolone, and cyclopropyl groups attacked by reactive oxygen species. In this work, we built cobalt-based composite nanomaterials to promote effective electron transfer and minimize leaching of cobalt ions, and providing a new method for activating PMS in a continuous flow system by enriching the oxygen vacancies in the catalytic membrane. This method has potentials to be applied in treating wastewater containing antibiotics such as CIP.

Adsorptive removal of ciprofloxacin from simulated wastewater using crosslinked starch ester: Isotherms, kinetics, thermodynamics, modeling, and simulation for continuous operation

The rise in fluoroquinolone concentrations in wastewater caused significant concern due to their potential acute toxicity to living organisms. A novel eco-friendly adsorbent, crosslinked potato starch ester, was used to remove ciprofloxacin from a simulated aqueous solution by a batch adsorption process and used its obtained parameters to solve mathematical modeling. With a maximum adsorption capacity of 243.90 mg/g, the ciprofloxacin adsorption on crosslinked potato starch ester was suitable for the Langmuir isotherm model. The kinetics of ciprofloxacin adsorption showed that the pseudo-first-order kinetic model was a good fit for the adsorption process. Thermodynamic parameters exhibited that ciprofloxacin adsorption onto crosslinked potato starch ester was exothermic, achievable, and spontaneous. Finally, the process is simulated under various operating conditions using the mathematical model of a fixed bed continuous adsorption column. According to the results, under optimal operation conditions of inlet fluid velocity, particle size, bed height, and initial ciprofloxacin concentration with values 0.002 m/s, 1.2 mm, 0.2 m, and 143.4 mg/L, respectively, the highest dynamic adsorption capacity was 18.75 mg/g.

Optimization of Visible-Light-Driven Ciprofloxacin Degradation Using a Z-Scheme Semiconductor MgFe2O4/UiO-67.

A heterogeneous photocatalyst, MgFe2O4/UiO-67 (MU-x), was successfully synthesized by doping magnetic magnesium ferrite nanoparticles (MgFe2O4) with the UiO-67 metal-organic framework at various weight ratios (MgFe2O4: UiO-67 at 30, 50, 70, and 90 wt %). Various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) , Brunauer-Emmett-Teller (BET), photoluminescence (PL), vibrating sample magnetometry (VSM), electrochemical impedance spectroscopy (EIS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), were used to characterize the prepared photocatalysts. The photocatalytic performance of MU-x in the degradation of ciprofloxacin (CIP) under visible light was assessed. The CIP degradation efficiency was found to increase as the amount of MgFe2O4 in the composite was increased up to 70 wt %. Experimental conditions were optimized using response surface methodology (RSM) based on central composite design (CCD) with three factors: initial pH, catalyst loading, and CIP concentration. Using the obtained model, the optimal conditions were determined as follows: initial pH of 8.025, catalyst loading of 33.8 wt %, and CIP concentration of 10.8 mg/L. Under these optimal conditions, a notable improvement was achieved, with 99.62% of CIP removal achieved within 90 min, surpassing the performance of previously reported photocatalysts. Total organic carbon (TOC) analysis revealed a high degree of mineralization, at 81.25%. The degradation pathway of CIP was investigated based on liquid chromatography-mass spectrometry (LC-MS) analysis. Finally, the values of ECB and EVB of the photocatalyst were determined and the possible degradation mechanism of CIP was investigated based on Mott-Schottky and the applied scavengers. The hydroxyl radical (•OH) was identified as the dominant species in the removal of CIP through a trapping experiment. The photocatalyst with 70 wt % of MgFe2O4 (MU-70) exhibited excellent stability and recoverability with an external magnet, demonstrating 86.33% CIP removal after four cycles. According to the obtained results, MU-70 is a promising visible-light-active photocatalyst with great potential for water treatment applications and convenient recovery.

Removal of Ciprofloxacin Antibiotic from Synthesized Aqueous Solution Using Three Different Metals Nanoparticles Synthesized Through the Green Method

This study investigates the possibility of removing ciprofloxacin (CIP) using three types of adsorbent based on green-prepared iron nanoparticles (Fe.NPs), copper nanoparticles (Cu. NPS), and silver nanoparticles (Ag. NPS) from synthesized aqueous solution. They were characterized using different analysis methods. According to the characterization findings, each prepared NPs has the shape of a sphere and with ranges in sizes from of 85, 47, and 32 nanometers and a surface area of 2.1913, 1.6562, and 1.2387 m2/g for Fe.NPs, Cu.NPs and Ag.NPs, respectively. The effects of various parameters such as pH, initial CIP concentration, temperature, NPs dosage, and time on CIP removal were investigated through batch experiments. The results showed that 10 mg/L CIP was removed by 100%, 92% and 79% within 180 min using Fe.NPs, Cu.NPs, and Ag.NPs respectively. In addition to this, kinetic models of the adsorption and mechanism of CIP removal were studied. The cinematic analysis demonstrated that adsorption is a physics adsorption mechanism with an energy of 0.846 kJ.mol-1, 1.720 kJ.mol-1, and 3.872 kJ.mol-1, while the low activation energies of 17.660 kJ.mol-1, 13.221 kJ.mol-1, and 14.060 kJ.mol-1 for Fe.NPs, Cu.NPs, and Ag.NPs respectively. The kinetic removal process follows a pseudo-first-order model following a physical diffusion-controlled reaction. The data on adsorption was analyzed using the Langmuir, Freundlich, Temkin, and Dubinin models, as well as thermodynamic factors, indicating that the process is appropriate and endothermic sorption. The most practical adsorbent was Fe.NPs

Optimization of the removal of the antibiotic ciprofloxacin by composite aerogels based on PVA/agar/maltodextrin

In this study, we used a synthetic aerogel based on PVA/agar/maltodextrin to remove the antibiotic ciprofloxacin (CFX) from aqueous media. Response surface method (RSM) is used to study the relationship between the factors affecting the adsorption process, thereby optimizing the adsorption efficiency, and making decisions on improving the adsorption process better sub. The research results obtained are as follows: pH2, initial CFX concentration 51 mg L−1, adsorbent dosage 0.16 g L−1, adsorption time 120 min, and temperature 51.5 °C reached the maximum adsorption capacity. The maximum additive is 38.63 mg g−1. The experimental data agree with the pseudo-quadratic kinetic model and the Langmuir and Temkin isotherm models. The composite aerogel adsorbent (AE) in this study is a potential candidate for adsorbent to remove antibiotic contamination in aqueous media.

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.

Synthesis of a novel HoFeO3/Ho3Fe5O12 nanoadsorbent for efficient absorption of ciprofloxacin from liquid-phase: Modeling and optimization using response surface methodology

In this research, a new magnetic nano adsorbent was prepared for the absorption of the ciprofloxacin antibiotic from aqueous media. Also, some parameters affecting the absorption such as time, pH, the concentration of ciprofloxacin, and the nano adsorbent dose, were investigated. A response surface methodology (RSM) based on a central composite design (CCD) was used to determine the optimum points in the ciprofloxacin adsorption and create a valid mathematical model to predict the absorption of ciprofloxacin by the new nano adsorbent. The structure and morphological properties of the synthesized adsorbent were characterized by some special analysis. After determining the optimal points, the kinetics, isotherm and the recovery rate of the adsorbent were also investigated. The results showed that the quadratic model described the best adsorption of ciprofloxacin onto nano adsorbent, and the R2, adjusted R2, and predicted R2 were 0.9867, 0.9808, and 0.9622, respectively. Under optimized conditions (time 45 min, adsorbent dosage 700 mg/L, pH 5, initial ciprofloxacin concentration 25 mg/L), the removal efficiency with a desirability factor of 1 was 91.50 %, and the predicted one was 90.49%. Also, the process follows the quadratic model and the Langmuir isotherm. The recovery results determined that the absorption rate after 5 consecutive cycles is still close to 80%. Therefore, it can be concluded that the new nano adsorbent can be an efficient adsorbent in removing ciprofloxacin from aquatic environments.

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.

Enhanced visible-light-responsive photodegradation of ciprofloxacin by direct Z-scheme ZnFe2O4@g-C3N4 nanocomposites

The zinc ferrite@graphitic carbon nitride (ZnFe2O4@g-C3N4, ZFO@CN) nanocomposites were fabricated as the direct Z-scheme heterostructured photocatalysts for the enhanced visible-light-driven photodegradation of ciprofloxacin (CIP). The 15 – 30 nm ZFO, fabricated from the nonaqueous hydrothermal method, is well-distributed on the sheet-like CN structure, resulting in the high specific surface and mesoporosity with increased surface-to-volume ratio and reactive sites. Moreover, the heterojunction interface between ZFO and CN enhances the visible light response as well as decreases the electron–hole recombination, and subsequently increases the photodegradation performance of CIP over ZFO@CN. A nearly complete removal efficiency with a rate constant of 0.047 min−1 for CIP photodegradation is observed. The environmental parameters including pH, initial CIP concentration, inorganic anions and water matrices were examined to optimize the photocatalytic activity of the ZFO@CN nanocomposite. The ZFO@CN nanocomposite exhibits excellent structural and physicochemical stability and good reusability over 5 cycles. The radical trapping results signify that O2− and h+ are the primarily responsible radicals for the enhanced degradation of CIP over direct Z-scheme ZFO@CN heterojunction. Results clearly elaborate on the superiority of ZFO@CN over the photodegradation of CIP, which can serve as the platform for the fabrication of metal oxide@CN as the Z-scheme heterojunction for water and wastewater purification.

Fabrication of highly effective Ag6Si2O7/SmFeO3 heterojunction with synergistically enhanced sonophotocatalytic degradation of ciprofloxacin and production of H2O2: Influencing factors and degradation mechanism

The design of an effective catalyst for refractory pollutant destruction and H2O2 production remains a major challenge. In this study, a number of novel Ag6Si2O7/SmFeO3 (ASF) heterojunction catalysts were rationally fabricated through an in-situ precipitation strategy. The properties of the fabricated ASF nanocomposites were confirmed through different characterization techniques. In particular, the ASF-1.5 sample exhibits excellent sonophotocatalytic efficiency (94.9%) in an initial ciprofloxacin (CIP) concentration of 10 mg/L, a catalyst dosage of 0.6 g/L, US power of 400 W, pH of 5.0, and US frequency of 40 kHz within 60-min irradiation. Furthermore, the optimized ASF-1.5 sample exhibited the best H2O2 production rate of 258.5 μM, which was 2.92-fold higher than that of bare Ag6Si2O7. Scavenging experiments demonstrated that •OH and h+ were the primary reactive oxidative species (ROS) in the CIP abatement reaction. The synergistic effect of ultrasound and visible light can then promote ROS production, enabling the ASF-1.5 heterojunction to exhibit superior efficiency in CIP degradation and H2O2 generation. Moreover, a tentative sonophotocatalytic mechanism and potential routes for CIP degradation were established. To summarize, this study provides new insights into the rational design of highly effective ASF sonophotocatalysts for clean energy production and ecological applications.