Removal Efficiency Of Norfloxacin Research Articles

Interfacial engineering and vacancy design of quasi-2D NiCoAl-LDH/Kaolin hybrid for activating peroxymonosulfate to boost degradation of antibiotics

Oxygen vacancies are prevalent in metal compounds and play a significant role in the activation of peroxomonosulfate (PMS) to mitigate water pollution. However, how to easily construct these oxygen vacancies and elucidate the mechanism of PMS activation by oxygen vacancies are still pending research and solution. This study presents the synthesis of a NiCoAl-LDH/Kaolin (NiCoAl-LDH/Kao) hybrid catalyst with quasi-2D layer structures morphology and abundant oxygen vacancies (OVs) for activating peroxymonosulfate (PMS). We proposed an intriguing phase transformation from NiCo-carbonate hydroxide (CH) to NiCoAl-layered double hydroxide (LDH), and elucidated the morphological evolution mechanism from nanorod to nanosheet structures through alkaline etching. The NiCoAl-LDH/Kao-PMS system exhibited excellent rapid kinetics and removal efficiency of norfloxacin (NOR), degrading 92.0 % of NOR within 10 min and achieving a final degradation rate of 97.2 %, along with remarkable reusability performance of the NiCoAl-LDH/Kao catalyst. Furthermore, reactive oxygen species including sulfate radical (SO4−), hydroxyl radical (OH), superoxide anion (O2−) and singlet oxygen (1O2) were found to be involved in the degradation process of NOR, and the degree of activity of the active groups from strong to weak is 1O2, SO4−, O2− and OH. The activation mechanism and conceivable degradation pathways of NOR were experimentally studied and proposed, and the toxicity of degradation intermediates was evaluated. The facile preparation method for NiCoAl-LDH/Kao nanocomposite holds potential for large-scale manufacturing in organic pollutant remediation, while also providing new insights on the indispensable role of OVs in heterogeneous catalysis.

Exploring the Potential of Biochar Derived from Chinese Herbal Medicine Residue for Efficient Removal of Norfloxacin.

One-step carbonization was explored to prepare biochar using the residue of a traditional Chinese herbal medicine, Atropa belladonna L. (ABL), as the raw material. The resulting biochar, known as ABLB4, was evaluated for its potential as a sustainable material for norfloxacin (NOR) adsorption in water. Subsequently, a comprehensive analysis of adsorption isotherms, kinetics, and thermodynamics was conducted through batch adsorption experiments. The maximum calculated NOR adsorption capacity was 252.0 mg/g at 298 K, and the spontaneous and exothermic adsorption of NOR on ABLB4 could be better suited to a pseudo-first-order kinetic model and Langmuir model. The adsorption process observed is influenced by pore diffusion, π-π interaction, electrostatic interaction, and hydrogen bonding between ABLB4 and NOR molecules. Moreover, the utilization of response surface modeling (RSM) facilitated the optimization of the removal efficiency of NOR, yielding a maximum removal rate of 97.4% at a temperature of 304.8 K, an initial concentration of 67.1 mg/L, and a pH of 7.4. Furthermore, the biochar demonstrated favorable economic advantages, with a payback of 852.5 USD/t. More importantly, even after undergoing five cycles, ABLB4 exhibited a consistently high NOR removal rate, indicating its significant potential for application in NOR adsorption.

Novel Sb-doped cobalt oxide as a catalyst on peroxymonosulfate activation to degrade organic pollutants efficiently

Novel Sb-doped cobalt oxides (SCO) with dual active sites were fabricated by sol-gel combustion way and characterized via various analytical methods, which presented excellent performance as catalysts for activating peroxymonosulfate (PMS) to remove refractory pollutants. Among the materials with different doping ratios, the SCO catalyst with the molar ratio of Sb/Co = 0.2 (SCO-3) showed the most remarkable activity. In the SCO-3/PMS system, the removal efficiency of norfloxacin (NOR) was 91.2 % with 0.06 g/L SCO-3 and 0.24 g/L PMS at neutral pH in 40 min. Nearly 100 % of tetracycline (TC) and rhodamine B (RhB) were eliminated within 40 min and 5 min under the same condition, respectively. Attributed to the modified surface structure, enhanced electron transfer ability, and various reactive oxygen species (ROS), SCO-3 possessed good performance on PMS activation for removing various refractory pollutants. Furthermore, it was demonstrated that the dominating ROS were SO4-·, ·O2-, and 1O2, which were generated by the activation of the Sb and Co sites on PMS. Eventually, based on some experiments and analysis, the reusability, stability, and degradation pathway were determined. This work promoted a foundation for applying Sb-Co heterogeneous catalysts in organic wastewater treatment during the PMS oxidation process for the first time.

Catalytic Ozonation of Norfloxacin Using Co-Mn/CeO2 as a Multi-Component Composite Catalyst

In this study, a Co-Mn/CeO2 composite was prepared through a facile sol-gel method and used as an efficient catalyst for the ozonation of norfloxacin (NOR). The Co-Mn/CeO2 composite was characterized via XRD, SEM, BET and XPS analysis. The catalytic ozonation of NOR by Co-Mn/CeO2 under different conditions was systematically investigated, including the effect of the initial solution’s pH, Co-Mn/CeO2 composite dose, O3 dose and NOR concentration on degradation kinetics. Only about 3.33% of total organic carbon (TOC) and 72.17% of NOR could be removed within 150 min by single ozonation under the conditions of 60 mg/L of NOR and 200 mL/min of O3 at pH= 7 and room temperature, whereas in the presence of 0.60 g/L of the Co-Mn/CeO2 composite under the same conditions, 87.24% NOR removal was obtained through the catalytic ozonation process. The results showed that catalytic ozonation with the Co-Mn/CeO2 composite could effectively enhance the degradation and mineralization of NOR compared to a single ozonation system alone. The catalytic performance of CeO2 was significantly improved by the modification with Mn and Co. Co-Mn/CeO2 represents a promising way to prepare efficient catalysts for the catalytic ozonation of organic polluted water. The removal efficiency of NOR in five cycles indicates that Co-Mn/CeO2 is stable and recyclable for catalytic ozonation in water treatment.

Electro-Chemical Degradation of Norfloxacin Using a PbO2-NF Anode Prepared by the Electrodeposition of PbO2 onto the Substrate of Nickel Foam

A novel three-dimensional network nickel foam/PbO2 combination electrode (PbO2-NF) with high electrochemical degradation efficiency to norfloxacin was successfully fabricated through the electrodeposition of PbO2 on the substrate of nickel foam. The characterization of an PbO2-NF electrode, including surface morphology, elemental components, electrochemical performance, and stability was performed. In electrochemical oxidation tests, the removal efficiency of norfloxacin (initial concentration for 50 mg/L) on PbO2-NF reached 88.64% within 60 min of electrolysis, whereas that of pure nickel foam was only 30%. In the presence of PbO2-NF, the optimum current density, solution pH, electrode spacing for norfloxacin degradation were 30 mA/cm2, 11, and 3 cm, respectively. The electric energy consumption for 80% norfloxacin was approximately 5 Wh/L. Therefore, these results provide a new anode to improve the removal of norfloxacin in the wastewater with high efficiency and low energy consumption.

Deep oxidation of norfloxacin by the electrochemical enhanced heterogeneous catalytic oxidation: The role of electric field and reaction optimization.

In this study, electrochemical (ECG-G: graphite anode and cathode, ECI-G: iron anode and graphite cathode) enhanced heterogeneous activation of peroxymonosulfate (PMS) by CoFe2O4 nanoparticles for the degradation of norfloxacin (NOR) in water was investigated. Although a higher NOR removal efficiency was achieved in ECI-G/CoFe2O4/PMS system, the generation of Fe3+ had resulted in the deposition of iron mud and affect the recovery of CoFe2O4. Under the optimum reaction conditions of CoFe2O4/PMS system, the final removal efficiency of NOR did not show significant difference in ECG-G/CoFe2O4/PMS system (96.0%) and CoFe2O4/PMS system (95.5%), but the value of apparent rate constant significantly increased in ECG-G/CoFe2O4/PMS system (0.21min-1) compared with CoFe2O4/PMS system (0.11min-1). Similar NOR degradation pathways were obtained in these two systems, and the TOC removal efficiency in ECG-G/CoFe2O4/PMS system (28.8%) is almost as low as CoFe2O4/PMS system (26.0%). Therefore, it can be proposed that the applied electric field through active electrodes can accelerate the reaction of heterogeneous catalytic oxidation, but does not participate much in NOR degradation. However, the TOC removal efficiency (30min) could be reached 68.7% as the mass ratio of PMS to CoFe2O4 increased to 5:1 (250mgL-1: 50mgL-1). The ECG-G/CoFe2O4/PMS system is a promising low-cost technique for efficient mineralization of antibiotics in wastewater.

Understanding and characteristics of coagulation removal of composite pollution of microplastic and norfloxacin during water treatment

Water composite pollution is still a great challenge in the field of water treatment. Especially for microplastic (MP), as an emerging pollutant, its wide distribution in water and persistent eco-environmental influence have received great concerns in recent years. Nevertheless, the removal characteristics and mechanism of conventional coagulation on MP composite pollution is quite insufficient. In this study, the coagulation removal performance and mechanisms of MP (polyethylene, PE) and norfloxacin (NOR) was investigated by polyaluminium chloride (PAC) and anionic polyacrylamide (APAM). Compared with single system, the removal efficiency of PE was significantly improved (>99.0%) under plateau stage in composite system, while the removal efficiency of NOR was slightly decreased to around 42% regardless of the addition of APAM. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), zeta potential and One-way analysis of variance (ANOVA) of experimental data were used to explore the coagulation mechanisms. The results demonstrated that the removal of individual PE and NOR was mainly controlled by charge neutralization and sweep flocculation by PAC and APAM, and adsorption by formation of Al-NOR complex, respectively. Importantly, in composite system, the removal of PE was enhanced not only by the stronger charge neutralization but also the adsorption via the formation of PE-NOR-Al complex. Furthermore, the removal efficiency of PE and NOR in neutral and weak alkaline conditions was higher than that in weak acidic or strong alkaline conditions. The presence of metal ions and humic acid had obvious inhibition and promoting effects on the removal efficiency of PE and NOR. This study can provide a new perspective on fundamental understanding in characteristics and mechanisms of MP composite pollutants removed by coagulation.

Laccase inducer Mn2+ inhibited the intracellular degradation of norfloxacin by Phanerochaete chrysosporium

The effect of extracellular enzyme inducers such as Mn2+ on the intracellular degradation system of white-rot fungi is still unknown. In this study, the effect of Mn2+ on the degradation of norfloxacin (NOR) by Phanerochaete chrysosporium (P. chrysosporium) and its mechanisms were investigated. A higher concentration of Mn2+ led to higher adsorption of NOR but weaker degradation of NOR and, ultimately, lower removal efficiency of NOR by P. chrysosporium. The addition of Mn2+ increased the activities of both laccase (Lac) and manganese peroxidase (MnP), but only Lac played a role in the degradation of NOR, indicating that Mn2+ probably induced a greater contribution of extracellular Lac to NOR degradation by P. chrysosporium. Further investigation demonstrated that Mn2+ displayed a similar inhibitory effect on NOR degradation as the cytochrome P-450 inhibitor 1-aminobenzotriazole (ABT). Mn2+ inhibited the oxidation of the piperazine ring of NOR by P. chrysosporium, which resulted in similar changes in degradation products to those in the ABT-added group. These findings demonstrated that Mn2+ inhibited the intracellular degradation of NOR by cytochrome P-450.

Preparation of metal organic framework derived materials CoFe2O4@NC and its application for degradation of norfloxacin from aqueous solutions by activated peroxymonosulfate

The metal organic framework derived materials (CoFe2O4@NC) activated peroxymonosulfate (PMS) to degrade Norfloxacin (NOR) owing to the characteristics of high surface area (109.658 m2 g−1) and abundant mesoporous structure. The characterization results demonstrated that the optimal ratio of bimetal and of bimetallic to organic ligands (M/O) had good crystal structure and stability (Fe/Co = 3:1, M/O = 2:1). Moreover, NOR (10 mg L−1) removal of 98.78% was achievable in 60 min with an optimum concentration of PMS (0.32 mM) and dosage of CoFe2O4@NC (0.1 g L−1). The radical quenching results suggested that SO4·-, ·OH and 1O2 functioned in the presence of the system certificated by XPS spectra. The presence of Cl− and CO32−/HCO3− promoted the catalyst reaction. The recoverability revealed high removal efficiency of NOR of 93.55% could still be maintained. Furthermore, four pathways of NOR degradation were proposed, including dehydroxylation, defluorination, quinolone group conversion and piperazine ring transformation, which were attributed to the synergy of reactive oxygen species. The above results highlight that the method is of great significance to the practical application of heterogeneous catalysts in aqueous solutions.

Degradation of norfloxacin by hydroxylamine enhanced fenton system: Kinetics, mechanism and degradation pathway

This study demonstrated a fast and efficient degradation of a typical antibiotic norfloxacin (NOR) in a hydroxylamine enhanced Fenton (HA-Fenton) system, which showed a higher catalytic activity over a wider pH range (3.0–9.0). The removal efficiency of NOR was 96% at following conditions: 10 mg/L NOR, 10 μM Fe2+, 1.0 mM H2O2, 0.4 mM HA and pH 5.0. The degradation rate of NOR in the HA-Fenton system (0.23 min−1) was 10.9 times of that (0.021 min−1) in Fenton system. The addition of HA to Fenton system accelerated the conversion of Fe3+ to Fe2+, leading to the high concentration of ·OH in the HA-Fenton system. Ten degradation transformation products were detected by ultra-performance liquid chromatography tandem quadrupole time of flight mass spectrometer (UPLC-QTOF-MS), consequently, three main degradation steps were proposed, including defluorination, quinolone group transformation, and defluorination and piperazinyl ring opening. Further analyses of NO3−, NO2− and F− after the reaction indicated that defluorination process was the crucial degradation step. The HA-Fenton system might offer an efficient alternative for degradation of antibiotics in wastewater.

Assessment of degradation characteristic and mineralization efficiency of norfloxacin by ionizing radiation combined with Fenton-like oxidation

In this study, the degradation of norfloxacin was investigated by ionizing radiation combined with Fenton-like oxidation in order to enhance the degradation and mineralization of norfloxacin. The result showed that the removal efficiency of norfloxacin was 100%, 81.8%, 64.5%, 51.9%, and 45.6% at 0.4 kGy radiation when its concentration was 5, 10, 20, 30, and 40 mg/L. Norfloxacin could be completely degraded over pH range of 3.06–10.96 at 2 kGy radiation. The presence of inorganic anions had obvious influence on the degradation of norfloxacin, which decreased from 89.4% to 59.0%, 76.9%, 86.9%, 88.7% and 83.9% in the presence of 10 mmol/L CO32–, HCO3–, NO3–, SO42–, Cl–, HPO42–. The removal efficiency of norfloxacin decreased from 100% to 11.8%, 27.6% and 89.3% in the presence of peptone, glucose, and humic acid. The addition of Fenton-like catalysts, such as magnetite and goethite, could improve the mineralization ratio of norfloxacin because they could decompose hydrogen peroxide generated during the radiation process, to form hydroxyl radicals, leading to the enhancement of removal efficiency of norfloxacin. Finally, the intermediate products of norfloxacin degradation were analyzed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF), and the degradation pathway was proposed.

Efficient removal of norfloxacin in water using magnetic molecularly imprinted polymer

Effective and practical materials are important for the pollution control in the environment. A novel magnetic molecularly imprinted polymer (CoFe2O4@TiO2-MMIP) was prepared based on the surface molecular imprinting technology combined with photocatalytic degradation and magnetic separation. The adsorption rate constant and maximum adsorption capacity of CoFe2O4@TiO2-MMIP are 0.21 g mg−1 min−1 and 14.26 mg g−1, respectively. The effects of experimental factors on the adsorption properties of the magnetic molecularly imprinted polymer were investigated. CoFe2O4@TiO2-MMIP had selective adsorption ability towards fluoroquinolones. The adsorption efficiency was closely related to the molecular structure, molecular weight, polarity and functional groups of the target contaminant and the removal efficiency of norfloxacin was affected by another substance obviously in binary adsorption system. The adsorption-photocatalytic recycling experiment verified that CoFe2O4@TiO2-MMIP could simultaneously complete the degradation of pollutants and in-situ regeneration, indicating good reusability. This material with selective adsorption and photocatalytic regeneration would have substantial attraction for application in the removal of fluoroquinolones.

High-efficiency adsorption of norfloxacin using octahedral UIO-66-NH2 nanomaterials: Dynamics, thermodynamics, and mechanisms

Antibiotics abuse has been a significant threat to the environment and human health. In this study, we successfully synthesized highly stable amino-functionalized Zr-based metal–organic frameworks (UiO-66-NH2) and studied the adsorption behaviors of norfloxacin (NOR) in water. The adsorption capacities of UiO-66-NH2 reached a maximum of 222.5 mg/g for NOR, which were considerably higher than that of most reported adsorbents. Moreover, the equilibrium time (6 h) was less than that of several previously reported adsorbents. Ionic-strength-influenced experiments showed that NaCl and CaCl2 aqueous solutions could improve the removal efficiency of NOR. The presence of humic acid could barely affect the adsorption amount. At a concentration of 10 mg/L, the highest partition coefficient of 20.9 mg/g/µM was obtained, and the removal rate of NOR was as high as 91.6%, implying that UiO-66-NH2 offered considerable adsorption performance at a low concentration of NOR. In addition, UiO-66-NH2 exhibited good regeneration efficiency, thus offering the possibility to remove norfloxacin from sewage. Finally, several credible adsorption mechanisms were proposed. The results will aid us to comprehend the surface interaction between organic micropollutants and UiO-66-NH2 and prefigure the potential of UiO-66-NH2 as a novel adsorbent for the removal of NOR.

Degradation of antibiotics by modified vacuum-UV based processes: Mechanistic consequences of H2O2 and K2S2O8 in the presence of halide ions

In this work, the degradation of cefalexin, norfloxacin, and ofloxacin was examined via various advanced oxidation processes (AOPs). Direct photolysis by ultraviolet (UV) and vacuum ultra violet (VUV) was less effective for the degradation of fluoroquinolone antibiotics such as norfloxacin and ofloxacin than that of cefalexin. Both hydrogen peroxide (H2O2) and potassium persulfate (K2S2O8) assisted UV/VUV process remarkably enhanced fluoroquinolone degradation. The addition of K2S2O8 was superior to H2O2 under VUV irradiation, with the best removal efficiency of norfloxacin and ofloxacin being almost 100% within 3 min in the presence of VUV/K2S2O8. The ofloxacin degradation rate was accelerated as concentrations of H2O2 and K2S2O8 was increased to 3 mM, but the degradation rate was slightly decreased with excess H2O2 (>3 mM). The performance of modified VUV processes (i.e., VUV/H2O2 and VUV/K2S2O8) was inhibited at highly alkaline condition (pH 11). The co-existence of halides (Cl− and Br−) enhanced antibiotics degradation via the modified VUV processes, but the reaction was almost unaffected in the presence of single halides. This study demonstrated that modified VUV processes (especially VUV/K2S2O8) are efficient for eliminating fluoroquinolone antibiotics from water, which can be considered as a clean and green method for the treatment of antibiotics-containing industrial wastewater.

Flower-like BiOBr/UiO-66-NH2 nanosphere with improved photocatalytic property for norfloxacin removal

Metal–organic frameworks (MOFs) have attracted widespread concerns in the photocatalysis research. However, MOFs-based photocatalyts for antibiotics treatment are still very limited. There are also few reports on selecting MOFs as supports to regulate the morphology of Bismuthoxyhalides. In this study, BiOBr/UiO-66-NH2 composites with three-dimensional structure of flower-like nanosphere were fabricated via a facile synthetic route. Various characterizations, such as XRD, SEM and XPS, proved the successful synthesis of composite and revealed that BiOBr nanoplates grow on the surfaces of the UiO-66-NH2 with an intimate interaction. A typical fluoroquinolones antibiotics, norfloxacin (NOR) was selected to estimate the photocatalytic efficiency of the BiOBr/UiO-66-NH2 complex. A series of the composites all exhibited higher NOR removal performance than the pure components and mechanically mixed sample under simulated sunlight. Among them, the composite with UiO-66-NH2 content of 20 w% (BUN-20), had good structural stability and the best performance on the removal of NOR. The removal efficiency of NOR (10 mg/L) over BUN-20 (0.3 g/L) was 93.60% within 180 min irradiation. Three factors during the fabricating process, such as increased surface active sites, improved photoadsorption capacity and lower recombination probability of electron-hole pair might be accountable for the meliorative photocatalytic performance. Ultimately, a plausible photocatalytic mechanism was also proposed.

Solar light driven degradation of norfloxacin using as-synthesized Bi3+ and Fe2+ co-doped ZnO with the addition of HSO5−: Toxicities and degradation pathways investigation

In this study, solar light responsive Bi3+ and Fe2+ doped ZnO were synthesized and used for photocatalytic degradation of norfloxacin (NOR), an emerging water pollutant. Analysis with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and UV–vis diffuse reflectance spectroscopy (DRS) confirmed coupling of dopants (i.e., Bi3+ and Fe2+) or co-dopants (Bi3+/Fe2+) with ZnO and suggested small narrow size as well as highly crystalline and porous nature of the doped ZnO. Metal ions doping lowered band gap energy and inhibited recombination of electron-hole pair in the as-synthesized ZnO. Consequently, BiFe-ZnO showed enhanced photocatalytic activity and reusability, giving 80% removal of NOR as compared to 36% by un-doped ZnO at a reaction time of 120 min. The analysis with photoluminescence (PL) technique verified high yield of OH from solar light activation of BiFe-ZnO compared to Bi-ZnO, Fe-ZnO and ZnO. Performance of the as-prepared photocatalysts was promoted with the added HSO5− and increased with increasing [HSO5−]0. Degradation of NOR by BiFe-ZnO with the added HSO5− was due to OH and SO4− and NOR showed high reactivity with OH and SO4−. The removal efficiency of NOR was inhibited using OH and SO4− scavengers. Photocatalytic activity of the as-synthesized photocatalysts with the added HSO5− was highly dependent on [NOR]0, [pH]0, co-existing ions, and natural organic matter. Degradation pathways were suggested from the pattern of NOR degradation and identified transformation products. The mineralization of NOR as well as formation of non-toxic end product suggests co-doped ZnO with added HSO5− to be a potential technology for treating antibiotics contaminated water.

Removal of norfloxacin using coupled synthesized nanoscale zero-valent iron (nZVI) with H2O2 system: Optimization of operating conditions and degradation pathway

Abstract In this study, nanoscale zero-valent iron (nZVI) was synthesized in the laboratory by the borohydride reduction method. nZVI was characterized by transmission electron microscopy (TEM), scan electronic microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). In addition, the degradation performance of norfloxacin (NOR) in nZVI/H 2 O 2 Fenton-like system was investigated in detail under various experimental conditions. It was found that the removal of NOR depended on its initial concentration, initial pH, temperature, H 2 O 2 concentration and nZVI dose. At the ambient temperature, the degradation rate of NOR by nZVI/H 2 O 2 Fenton-like reaction under the acidic medium (pH = 3–4) was more than 95% within 40 min of the reaction time, and the mineralization degree was around 50% in terms of total organic carbon (TOC) measurement. Optimal temperature for NOR removal was 308 K, and higher temperature would cause useless decomposition of H 2 O 2 and consequently reduction of NOR degradation. The degradation rate and total removal efficiency of NOR were favored by increasing the nZVI and H 2 O 2 dosages. The optimal conditions for NOR degradation were: initial pH = 4.0, H 2 O 2 concentration = 20 mmol/L, nZVI dose = 100 mg/L, temperature = 308 K. The rate constants ( K ob s ) of NOR degradation could be fitted well with a pseudo-second-order kinetic equation. Several degradation intermediates of NOR were detected and confirmed, including C 15 H 20 FN 3 O ( m / z 278), C 9 H 11 FN 2 ( m / z 167), C 7 H 7 FN 2 ( m / z 139), and C 7 H 8 FN ( m / z 126), respectively. Based on the identified intermediates and the Gaussian quantum statistics molecular bonding energy calculation, the possible pathway for NOR degradation under nZVI/H 2 O 2 Fenton-like reaction was discussed.

COUPLING OF MEMBRANE BIOREACTOR AND OZONATION FOR REMOVAL OF ANTIBIOTICS FROM HOSPITAL WASTEWATER

Antibiotic residues in the environment and their potential toxic effects have been considered as one of the emerging research area in the environmental field. Their continuous introduction in our environment may increase their negative impacts on human health. In this study, the eliminations of antibiotic such as Norfloxacin (NOR), Ciprofloxacin (CIP), Ofloxacin (OFL) and Sulfamethoxazole (SMZ) in wastewater of hospital were processed by membrane bioreactor (MBR) coupled with ozonation process. In particular, the MBR was applied for the antibiotic removals followed by ozonation process as a post-treatment stage to create an adequate integration to enhance removal efficiency. Achieved results after MBR treatment showed that the removal efficiency of NOR, CIP, OFL and SMZ were 90 ± 4.0% , 83 ± 13% , 81 ± 13 % and 39 ± 6%, respectivley. In addition, those antibiotic matters were continously removed by ozonation process with the removal efficiency of 87±9.0% , 83±1.0% , 81±2.3% and 66±2.3% for NOR, CIP, OFL and SMZ, respectively. In summary, antibiotics could be basically limited by the combination of MBR and ozonation before discharging in aquatic environment.

Optimization and Modeling of Photocatalytic Removal of Norfloxacin Using Tungsten Bismuth Loaded Carbon Iron Complexes Based on Response Surface Methodology

Photocatalytic degradation of norfloxacin (NOR) (10 mg/L) was studied using tungsten bismuth loaded carbon iron complexes (C/Fe–Bi2WO6) under simulated solar light (SSL) irradiation in a cylindrical reactor. Three experimental parameters were chosen as independent variables: pH, C/Fe–Bi2WO6 concentration, and H2O2 concentration. A central composite experimental design (CCD) was used to establish a quadratic model as a functional relationship between the removal efficiency of NOR and the three independent variables. The optimal values of operating parameters under the related constraint conditions were found at a pH of 7.10, a C/Fe–Bi2WO6 concentration of 0.78 g/L, and a H2O2 concentration of 227 mg/L. Under the optimal conditions, the removal efficiency of NOR reached 91.66%. Regression analysis with an R2 value of 0.9728 indicated a good correlation between the experimental results and the predicted values.