Enfin disponible en Europe, grâce à une étonnante formule Europe, 100% naturelle, vous pouvez maintenant dire stop à vos problèmes d’impuissance et à vos troubles de la virilité. Cette formule révolutionnaire agit comme un véritable achat cialis naturel. Ses résultats sont immédiats, sans aucun effet secondaire et vos érections sont durables, quelque soit votre âge. Même si vous avez plus de 70 ans !


Photocatalytical degradation of antibiotics in wastewater with nanoscaled TiO2 and UVA
Sara Teixeira, Klaus Kuehn, Lars Renner, and Gianaurelio Cuniberti
The presence of pharmaceuticals in water has become a great concern due to the potential negative effects on humans and aquatic ecosystems. From these pharmaceuticals, antibiotics represent a serious problem since its overuse and misuse may lead to adverse environmental effects, including the development of antibiotic resistance in microorganisms, toxicity to microflora and fauna and potential negative effects to humans [1-6].
Titanium Dioxide (TiO2) photocatalysis has become an attractive process to promote the degradation of contaminants in the aquatic environment since it allows their rapid and efficient removal from water, transforming them into by-products with lower toxicity [7-12].
Figure 1 represents the energy band diagram and fate of electrons and holes in a semiconductor particle in the presence of water pollutants. Electron–hole pairs are formed when photocatalysts are irradiated with equal or higher energy than its band gap, and the electron and hole will become spatially separated. The electron will be captured by O2 and the hole will be transferred by adsorbed hydroxide to form hydroxyl radicals.
In the present work a photocatalytic system using TiO2 Degussa P-25 in suspension was used to evaluate the degradation of four antibiotics: Amoxicillin, Penicillin G, Norfloxacin and Ciprofloxacin. Aqueous solutions of these antibiotics with different concentrations were prepared. 1 g L-1 of TiO2 Degussa P-25 was added to the antibiotic solutions as a catalyst. The antibiotic solutions were exposed for sixty minutes to UV irradiation (365 nm) under continuous stirring, set in a range from 1,7-1,9 mW cm-2 with the help of a Lux Meter. Samples were taken in defined time intervals. Prior to absorbance measuring the samples were filtered and centrifuged, in order to remove the TiO2 nanoparticles. The absorbance was then measured with an UV-VIS Spectrophotometer.
For all the tested antibiotics, the results showed that no degradation occurred by UV irradiation per se whereas with addition of TiO2 to the antibiotic aqueous solutions it is noticeable the antibiotics photodegradation, which suggests that TiO2 suspended in medium is a reliable photocatalyst, see figure 2.
It was also noticeable that Norfloxacin and Ciprofloxacin are faster photodegraded than Penicillin G and Amoxicillin. The data showed that with the increasing of antibiotics’ concentration the reactions rates decrease,
which means that more time is needed to complete degradation of the antibiotic in water.
[1] Homem, V. and Santos, L., Journal of Environmental Management, 92 (2011) 2304-2347.
[2] Madden, J. C., Enoch, S. J., Hewitt, M., and Cronin, M. T. D., Toxicology Letters, 185 (2009) 85-
[3] Cunningham, V. L., Binks, S. P., and Olson, M. J., Regulatory Toxicology and Pharmacology, 53
(2009) 39-45.
[4] Isidori, M., Bellotta, M., Cangiano, M., and Parrella, A., Environment International, 35 (2009) 826-
[5] Kümmerer, K., Journal of Environmental Management, 90 (2009) 2354-2366.
[6] Klauson, D., J. Babkina, Stepanova, K., Krichevskaya, M., and Preis, S., Catalysis Today, 151
(2010) 39-45.
[7] Faramarzpour M., Vossoughi, M., and Borghei, M., Chemical Engineering Journal, 146 (2009) 79-
[8] Fujishima, A., Rao, T. N., and Tryk, D., Journal of Photochemistry and Photobiology C:
Photochemistry Reviews, 1 (2000) 1–21.
[9] Haque, F., Vaisman, E., Langford, C., and Kantzas, A., Journal of Photochemistry and
Photobiology A: Chemistry, 169 (2005) 21–27.
[10] Kathiravan, A., Jhonsi, M., and Renganathan, R., Journal of Luminescence, 131 (2011) 1975–
[11] Klavarioti, M., Mantzavinos, D., and Kassinos, D., Environment International, 35 (2009) 402–417.
[12] Ray, A. and Beenackers, A., Catalysis Today, 40 (1998) 73–83.


Figure 1 – Diagram of the fate of electrons and holes in TiO2 in the water after excitation with UVA Figure 2 – Absorbance spectrum of Norfloxacin (4,7 mg L-1). On the right absorbance of Norfloxacin

Source: http://www.nanopt.org/12Abstracts/2012_Teixeira_Sara_sara.teixeira@nano.tu-dresden.de_NanoPT2013_Teixeira_Sara.pdf

3aih jun 12 pdf

In order to reduce the dose of prednisolone needed the doctor looking after you will often choose to start you, at some point, on an additional drug treatment. In most people the drug used is azathioprine (in some individuals other agents will be chosen). Azathioprine and related drugs are very effective at reducing the doses of prednisolone required to keep autoimmune hepatitis under control

Copia di layout

Vademecum organizzativo 1. Criteri generali a. Per costruire e mantenere il radica- occor e indicare come ar ivarci. mento sul ter itorio (che rappresenta uno d. L’identità del e parole d’ordine è il dei punti di forza del MFE), occor e che solo modo per far sì che azioni anchel’azione del a Sezione si indirizzi, nel diverse condot e da Sezioni diverse pos-tempo, verso tut i

Copyright © 2010-2014 Online pdf catalog