Photocatalytic Treatment Techniques using Titanium Dioxide Nanoparticles for Antibiotic Removal from Water (original) (raw)
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Journal of Engineering
The aim of this study was to investigate antibiotic amoxicillin removal from synthetic pharmaceutical wastewater. Titanium dioxide (TiO2) was used in photocatalysis treatment method under natural solar irradiation in a tubular reactor. The photocatalytic removal efficiency was evaluated by the reduction in amoxicillin concentration. The effects of antibiotics concentration, TiO2 dose, irradiation time and the effect of pH were studied. The optimum conditions were found to be irradiation time 5 hr, catalyst dosage 0.6 g/L, flow rate 1 L/min and pH 5. The photocatalytic treatment was able to destruct the amoxicillin in 5 hr and induced an amoxicillin reduction of about 10% with 141.8 kJ/L accumulated solar energy per liter of solution.
Titanium dioxide photocatalysis for pharmaceutical wastewater treatment
Environmental Chemistry Letters, 2014
Heterogeneous photocatalysis using the semiconductor titanium dioxide (TiO 2 ) has proven to be a promising treatment technology for water purification. The effectiveness of this oxidation technology for the destruction of pharmaceuticals has also been demonstrated in numerous studies. This review highlights recent research on TiO 2 photocatalytic treatment applied to the removal of selected pharmaceuticals. The discussions are tailored based on the therapeutic drug classes as the kinetics and mechanistic aspects are compound dependent. These classes of pharmaceuticals were chosen because of their environmental prevalence and potential adverse effects. Optimal operational conditions and degradation pathways vary with different pharmaceutical compounds. The main conclusion is that the use of TiO 2 photocatalysis can be considered a state-of-the-art pharmaceutical wastewater treatment methodology. Further studies are, however, required to optimize the operating conditions for maximum degradation of multiple pharmaceuticals in wastewater under realistic conditions and on an industrial scale.
Catalysts
The extensive application of antibiotics in human and veterinary medicine has led to their widespread occurrence in a natural aquatic environment. Global health crisis is associated with the fast development of antimicrobial resistance, as more and more infectious diseases cannot be treated more than once. Sulfamethoxazole, trimethoprim and ciprofloxacin are the most commonly detected antibiotics in water systems worldwide. The persistent and toxic nature of these antibiotics makes their elimination by conventional treatment methods at wastewater treatment plants almost impossible. The application of advanced oxidation processes and heterogeneous photocatalysis over TiO2-based materials is a promising solution. This highly efficient technology has the potential to be sustainable, cost-efficient and energy-efficient. A comprehensive review on the application of various TiO2-based photocatalysts for the degradation of sulfamethoxazole, trimethoprim and ciprofloxacin is focused on high...
Science of The Total Environment, 2013
j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c i t o t e n v organic carbon content was mainly due to low-molecular-weight carboxylate anions. After complete removal of the antibiotics, the remaining degradation by-products no longer showed antibacterial activity. Also, 10% and 55% of the nitrogen content of each antibiotic was converted to ammonium, while no conversion to nitrite or nitrate was detected. The presence of phosphates hindered considerably the removal of both antibiotics, whereas the presence of other inorganic ions did not substantially altered the antibiotics photocatalytic degradation kinetics.
Remediation of Antiseptic Components in Wastewater by Photocatalysis Using TiO2 Nanoparticles
ACS-Industrial Engineering & Chemistry Research
Environmental awareness in both the public and regulatory sectors has necessitated proper treatment of medicinal components-rich pharmaceutical effluents. Even the presence of trace antiseptic may cause adverse health effects including development of "product resistant microbes" in the aquatic environment. The present study involves photomineralization of chlorhexidine, which belongs to the class of antiseptic drug components. This study details investigations on photocatalytic degradation of chlorhexidine in a slurry batch reactor using titanium dioxide photocatalyst. Emphases were given to study the effects of operating parameters on the degradation behavior of the targeted compound and characterization of degraded products. About 68.14% removal of chlorhexidine digluconate (CHD) was found after 1 h at 25°C with a substrate-to-catalyst ratio of 2.5:1 under UV intensity of 50 μW·cm −2 at pH 10.5. Though the product profile illustrates several degraded products, toxicological analysis on Bacillus subtilis exhibited no inhibition zone, suggesting the eco-friendly nature of the degraded products.
Waste and Biomass Valorization, 2012
The adsorption and photocatalytic degradation of 15 different pharmaceuticals in the presence or absence of UV was comparatively studied using titanium dioxide (TiO 2 ) anatase and rutile nanowires as well as commercially available TiO 2 (P25) nanoparticles. Both anatase and rutile nanowires were grown under environmentally benign hydrothermal conditions. The kinetic adsorption studies demonstrate adsorption is usually complete within 20-40 min. The nanomaterials evaluated differed in photocatalytic efficiency by compound, with the UV-exposed anatase-phased nanowires being more effective at degrading venlafaxin, atorvastatin, ibuprofen, naproxen, gemfibrozil, lincomycin, norfluoxetine, diclofenac, and trimethoprim, while the rutile-phased nanowires were more effective for fluoxetine and norfluoxetine. The sole exposure to 265 nm UV leads to effectively decay sulfamethoxazole (SFX) and atrazine. Intermediate analysis unveils a higher mineralization of SFX is obtained with TiO 2 photocalytic degradation compared to the photolysis with a UVC at 254 nm. These initial studies provide mechanistic insight into the effectiveness of TiO 2 nanowires and nanoparticles for treatment of surface and drinking waters containing trace pharmaceutical residues.
TiO2-assisted photodegradation of pharmaceuticals — a review
Central European Journal of Chemistry, 2012
Pharmaceutical compounds have been detected in the environment and potentially arise from the discharge of excreted and improperly disposed medication from sewage treatment facilities. In order to minimize environmental exposure of pharmaceutical residues, a potential technique to remove pharmaceuticals from water is the use of an advanced oxidation process (AOP) involving titanium dioxide (TiO2) photocatalysis. To evaluate the extent UV/TiO2 processes have been studied for pharmaceutical degradation, a literature search using the keywords ‘titanium dioxide’, ‘photocatalysis’, ‘advanced oxidation processes’, ‘pharmaceuticals’ and ‘degradation’ were used in the ISI Web of Knowledge TM, Scopus TM and ScienceDirect TM databases up to and including articles published on 23 November 2011. The degradation rates of pharmaceuticals under UV/TiO2 treatment were dependent on type and amount of TiO2 loading, pharmaceutical concentration, the presence of electron acceptors and pH. Complete mine...
Bulletin of Chemical Reaction Engineering & Catalysis
In this study, the pure and calcined forms of Degussa TiO2 were applied for photocatalytic removal of doxycycline - a broad-spectrum tetracycline antibiotic. The calcination of TiO2 at 500 °C enhanced the photocatalytic efficiency of the TiO2 under optimal operational conditions of 5 ppm of doxycycline, 0.25 g/L of TiO2, pH 6.5, 120 min, and room temperature. In addition, the changes in morphology, crystal structure, and optical properties of the materials before and after calcination were observed by scanning electron microscopy, X-ray diffraction, and UV-Visible spectroscopy. The reaction kinetics of the doxycycline removal was also investigated based on the Langmuir-Hinshelwood model with a correlation coefficient R2 of >80%. Results showed that the photocatalytic ability of TiO2 is stable and enhanced after being calcined at a suitable temperature of 500 °C. This opens up the potential application of TiO2 in the treatment of emerging organic pollutants in water. Copyright © 2...