Titanium dioxide photocatalysis for pharmaceutical wastewater treatment (original) (raw)
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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...
Application of Titanium Dioxide, 2017
The increasing of emerging micropollutants presence in drinking water sources has brought new challenges to existing water treatment systems (WTS), highlighting the need of innovative and low-cost technological solutions. Recent advances in nanotechnology enable highly efficient and multifunctional processes, providing sustainable alternatives to current water treatment practices. This chapter presents the results of several pilot-scale studies developed to assess the effects of TiO 2 nanoparticles on antibiotic removal efficiency, using different low-cost photocatalytic reactors. The characterization of its photooxidation kinetics also performed considering different test scenarios in order to assess the effects of the major abiotic parameters on oxytetracycline (OTC) removal efficiency, which achieved the maximum values of 96% and 98% using the photocatalysis with TiO 2 and the photocatalytic filtration, respectively. It must be highlighted the surprising regeneration ability showed by the photocatalytic porous medium, developed at a lab-scale, which can completely recover its oxidative properties after few hours of simple sun exposure.
Photocatalytic Activity of TiO2 for the Degradation of Anticancer Drugs
Nanomaterials
To prevent water pollution, photocatalysis is often used to remove small molecules such as drugs by generating reactive species. This study aimed to determine the photocatalytic activity of two anticancer drugs, imatinib and crizotinib, and to investigate various influences that may alter the kinetic degradation rate and ultimately the efficacy of the process. In order to obtain optimal parameters for the removal of drugs with immobilized TiO2, the mutual influence of the initial concentration of the contaminant at environmentally relevant pH values was investigated using the response surface modeling approach. The faster kinetic rate of photocatalysis was obtained at pH 5 and at the smallest applied concentration of both drugs. The photocatalytic efficiency was mostly decreased by adding various inorganic salts and organic compounds to the drug mixture. Regarding the degradation mechanism of imatinib and crizotinib, hydroxyl radicals and singlet oxygen showed a major role in photoc...
Catalysis Today, 2006
A study of the photodegradation of different pharmaceuticals [furosemide, ranitidine (hydrochloride), ofloxacine, phenazone, naproxen, carbamazepine and clofibric acid] in aqueous medium at various pHs by using a batch photoreactor and a photocatalytic membrane reactor working in recirculation regime was carried out. Polycrystalline TiO2 was used as the photocatalyst, and different membranes (NTR 7410, PAN GKSS HV3/T, N 30 F, NF
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.
IOSR Journal of Engineering, 2016
This paper presents the photocatalytic degradation of real pharmaceutical wastewater from Abbot Laboratories (Private) Limited, Karachi, Pakistan, using TiO 2 , ZnO, and H 2 O 2. The pretreated sample wastewater was used for degradation experiments and tests were carried out at 38 0 C under pH of 9 and 4 in a stirrer bath reactor equipped with eight ultraviolet tubes. The use of this technique is common in removal of the organic, inorganic pollutants and pathogens. Optimal conditions were selected from reported results of the researchers on advanced oxidation processes (AOPs) for removal of residual pharmaceuticals from real pharmaceutical wastewater. The three catalysts (Titanium dioxide, zinc oxide, and TiO 2 / H 2 O 2) used in this study are effective catalysts in photocatalytic degradation of real pharmaceutical wastewater. The maximum degradation achieved was 45.11% by combined use of TiO 2 and H 2 O 2 at 38 0 C and pH. The degradation improved at higher pH with Zinc oxide and Titanium oxide. The results indicate that for real pharmaceutical wastewater, combined use of TiO 2 / H 2 O 2 is comparatively more effective than ZnO and TiO 2 alone. The degradation of the pharmaceutical wastewater followed pseudo-first-order kinetics. The reaction rate constant was 0.00148/min for TiO 2 / H 2 O 2. This study demonstrates that for real pharmaceutical wastewater reacts differently to catalyst than synthetic pharmaceutical wastewater, or formulated wastewater.
Photocatalytic Treatment of Pharmaceuticals in Water using Immobilized TiO2 and UV-A Irradiation
2015
The presence of pharmaceutically active compounds (PhACs) in the wastewater effluents has confirmed that conventional wastewater treatment technologies are not sufficiently effective in the pharmaceuticals' removal. The objective of the present study was to evaluate and compare the photocatalytic degradation of PhACs using TiO 2-P25, graphitic carbon nitride (g-C 3 N 4 , CN) and a heterojunction of perovskite strodium titanate and graphitic carbon nitride SrTiO 3 /g-C 3 N 4 (20% g-C 3 N 4 , 20CNSTO) photocatalytic materials, in hospital wastewater effluents, by simulated solar irradiation. The experiments were performed by using real wastewater samples collected from the university hospital wastewater treatment plant (WWTP) effluent of Ioannina city (Northwestern Greece) and inherent pharmaceutical concentration levels. The analysis of the samples was accomplished by solid phase extraction followed by liquid chromatography-Orbitrap high-resolution mass spectrometry. In the cases of TiO 2 and CN, more than 70% of the initial concentration (e.g., venlafaxine) was degraded after 90 min, while 20CNSTO presented lower photocatalytic performance. Furthermore, some compounds were sporadically detected (e.g., fluoxetine) or their concentrations remained stable during the photocatalytic treatment time period (e.g., trimethoprim). In total 11 transformation products (TPs) were formed along the degradation processes and were identified by using liquid chromatography high resolution mass spectrometry.
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...
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.