Azadeh Mehrdoost; Reza Jalilzadeh Yengejeh; Mohammad Kazem Mohammadi; Ali Akbar Babaei; Azadeh Haghighatzadeh
Abstract
Background: Pharmaceutical pollutants are one of the most important pollutants for water resources, and their health and environmental effects have been well estimated.Absorption is one of the best methods of the removal of antibiotics using nanocomposite.
Methods: This experimental study was performed ...
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Background: Pharmaceutical pollutants are one of the most important pollutants for water resources, and their health and environmental effects have been well estimated.Absorption is one of the best methods of the removal of antibiotics using nanocomposite.
Methods: This experimental study was performed on Nano composites. The PAC/Fe/Si/Zn Nano composite was successfully synthesized using a co-precipitation method in which iron (Fe), silicon (Si) and zinc (Zn) were loaded on the activated carbon powder (PAC). The structural features of the as-synthesized Nano composite were determined using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The as-synthesized Nano composite was utilized to remove azithromycin and cefixime from aqueous solution with the assistance of UV light. The effect of operational parameters such as pH, irradiation time, initial azithromycin/cefixime concentration and Nano composite dose on UV-assisted removal performance was evaluated using an optimization process.
Results: The UV-assisted removal activities indicated more removal percentage (99.7%) for azithromycin compared to cefixime (95.6%). The kinetics of removal was tested using Langmuir-Hinshelwood model, indicating the first-order reaction kinetics as the best model for UV-assisted removal of both azithromycin and cefixime. Adsorption equilibrium data were modeled using Langmuir and Freundlich isotherms. Azithromycin equilibrium adsorption showed a good fit with both Langmuir and Freundlich models, while the most suitable model for cefixime adsorption was estimated to be Langmuir isotherm.
Conclusion: The findings showed that PAC/Fe/Si/Zn Nano composite were well able to degrade non-biodegradable antibiotics in aqueous solutions, which is very valuable from environmental aspects.
Mohammad Ansarizadeh; Tayebeh Tabatabaei; Mohammad Reza Samaei; Mostafa Leili; Mohammad Mehdi Baneshi
Abstract
Background: Discharging antibiotics into the environment could cause great concern for scientists. In the present study, tetracycline (TC) antibiotic was photodegraded with titanium dioxide (TiO2) and zinc oxide (ZnO) fixed on the polyurethane (PU) in the presence of ultraviolet (UV) irradiation and ...
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Background: Discharging antibiotics into the environment could cause great concern for scientists. In the present study, tetracycline (TC) antibiotic was photodegraded with titanium dioxide (TiO2) and zinc oxide (ZnO) fixed on the polyurethane (PU) in the presence of ultraviolet (UV) irradiation and optimized through response surface methodology (RSM).
Methods: This experimental study was conducted on the most effective variables (pH, contact time, TC concentration, and catalyst doses) for experimental design. The experiments of degradation with the process of PU/UV/nanocatalyst composite were conducted with a reactor glass vessel (1000 mL) as batch mode.
Results: The results showed that the quadratic model can be used for the interpretation of experiments. The results of the model represented that all parameters had a significant effect on the tetracycline removal, and the degradation of antibiotics was obtained at the optimum condition that was 95% for ZnO/UV/PU and 97% for TiO2/UV/PU. The main radical for the degradation of TC was hydroxyl ions based on the scavenger study and the first-order kinetic model was best fitted with data. The highest removal efficiency was obtained at pH of 5.2, catalyst dose of 2.64g/m2, TC concentration of 25.21, reaction time of 82 min using ZnO/UV/PU and pH of 5.8, catalyst dose of 2.9 g/m2, TC concentration of 25.12, and reaction time of 90 min using TiO2/UV/PU.
Conclusion: It could be concluded that the process of nanocatalyst fixed on polyurethane can significantly eliminate the antibiotic in the presence of ultraviolet irradiation from the effluent of the wastewater treatment plant.
