Drugs degrading photocatalytically: Kinetics and mechanisms of ofloxacin and atenolol removal on titania suspensions

Hapeshi, Evroula; Achilleos, A.; Vasquez, Marlen I.; Michael, C.; Xekoukoulotakis, Nikolaos P.; Mantzavinos, Dionissios; Kassinos, Despo

doi:10.1016/j.watres.2009.11.044

Cited by 282 publications

(124 citation statements)

References 33 publications

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“…[47] The results are similar to a study on atenolol, where the same trend was observed. [48] Effect of solution pH The complex electrostatic interaction between semiconductor, solvent, substrate and charged radicals formed during the treatment make the pH an important reaction parameter. pH studies were thus conducted to determine the extent of degradation based on the ionisation state of the photocatalysts and DCF.…”

Section: Resultsmentioning

confidence: 99%

Photolysis and TiO2-catalysed degradation of diclofenac in surface and drinking water using circulating batch photoreactors

Kanakaraju¹,

Cherie²,

Motti³

et al. 2014

Environ. Chem.

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Environmental context. Diclofenac, a common non-steroidal anti-inflammatory drug, is not completely removed from surface and drinking water by conventional treatment methods. Consequently, this drug is present in the aquatic environment and has been subsequently linked to toxic effects on organisms. We show that photolysis and TiO 2 -catalysed degradation in circulating batch reactors efficiently results in diclofenac removal under a variety of conditions. These photochemical methods thus may lead to more effective water treatment processes.Abstract. The occurrence of diclofenac (DCF) as an emerging pollutant in surface waters and drinking water has been attributed to elevated global consumption and the inability of sewage treatment plants to remove DCF. In this study, DCF spiked drinking water and river water was subjected to photolysis and TiO 2 photocatalytic treatments in a circulating laboratory-scale (immersion-well) and a demonstration-scale loop reactor (Laboclean). The operational parameters for the immersion-well reactor were optimised as follows: TiO 2 P25 loading, 0.1 g L À1 ; natural pH, 6.2; initial concentration, 30 mg L À1 ; water type, distilled water. Complete DCF removal was realised within 15 min under the optimised conditions using the immersion-well reactor. Sunlight-mediated photochemical degradation required a prolonged exposure period of up to 360 min for complete DCF removal. DCF in distilled and drinking water was efficiently degraded in the larger Laboclean reactor. Differences were, however, observed based on their pseudo-first-order rate constants, which implies that the water matrix has an effect on the degradation rate. Six major photoproducts, 2-(8-chloro-9H-carbazol-1-yl)acetic acid, 2-(8-hydroxy-9H-carbazol-1-yl)acetic acid, 2,6-dichloro-N-o-tolylbenzenamine, 2-(phenylamino)benzaldehyde, 1-chloromethyl-9H-carbazole and 1-methyl-9H-carbazole, generated from TiO 2 photocatalysis of DCF were identified by liquid chromatography-mass spectrometry (LCMS) and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS). This work has shown that photocatalytic degradation kinetics of DCF are dependent on both the geometry of the photoreactor and the nature of the water matrices.

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Section: Resultsmentioning

confidence: 99%

Photolysis and TiO2-catalysed degradation of diclofenac in surface and drinking water using circulating batch photoreactors

Kanakaraju¹,

Cherie²,

Motti³

et al. 2014

Environ. Chem.

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“…pharmaceuticals) from water [7][8][9] and wastewater effluent [10,11], and as a water disinfectant [12,13]. The main limitation of TiO 2 is a relatively wide band gap, (3.02 eV for rutile, 3.2 eV for anatase) [14], which results in about 5% spectral overlap between its absorbance and sunlight emission (λ < ~390 nm).…”

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confidence: 99%

Impact of water quality on removal of carbamazepine in natural waters by N-doped TiO2 photo-catalytic thin film surfaces

Avisar¹,

Horovitz²,

Lozzi³

et al. 2013

Journal of Hazardous Materials

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“…Hapeshi et al 70 verificaram que 40% da ofloxacina (concentração inicial de 10 mg L -1 ) em água ultrapura foram degradadas sob radiação ultravioleta em 240 min. Não foi observada remoção de toxicidade da solução utilizando Daphnia magna como organismo teste.…”

Section: -69unclassified

“…Dada a baixa eficiência dos métodos convencionais e devido ao longo tempo de exposição à radiação ultravioleta necessário para a degradação de quinolonas, 11,14,58,59,[63][64][65][66][67][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86] conforme apresentado na Tabela 4, torna-se importante o estudo e a avaliação de tratamentos avançados.…”

Section: -69unclassified

“…Em ensaios agudos utilizando Daphnia magna, vários trabalhos na literatura reportam que concentrações maiores que 10 mg L -1 causam algum efeito em 50% nos microcrustáceos. 57,69,70 Atividade antimicrobiana A atividade antimicrobiana das quinolonas está relacionada com a formação de ligações de hidrogênio entre os grupos aceptores (COOH, C=O e F) desses compostos com o DNA-girase das bactérias, resultando na inibição da duplicação dos micro-organismos. O DNA-girase é uma enzima que evita o emaranhamento da fita de DNA da bactéria durante e após sua duplicação.…”

Section: Toxicidade E Atividade Antimicrobiana Residual Toxicidadeunclassified

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Occurrence and Degradation of Quinolones by Advanced Oxidation Processes

Rodrigues-Silva¹,

Maniero²,

Peres³

et al. 2014

Química Nova

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OCCURRENCE AND DEGRADATION OF QUINOLONES BY ADVANCED OXIDATION PROCESSES. In this review, the presence of quinolones in the environment, their risks and the available processes for water decontamination were addressed. Their occurrence in surface waters and also in soil raises concerns about the risk of the development of resistant bacteria and other potential chronic effects. AOPs (UV/H 2 O 2 , Fenton, photo-Fenton, and UV/TiO 2 ) and ozonation proved effective for degrading these emerging contaminants due to hydroxyl radical formation, surpassing the efficacy of conventional methods. In addition, the main degradation mechanisms of these drugs as well as data on residual biological activity were analyzed.Keywords: antimicrobials; degradation mechanisms; toxicity. INTRODUÇÃOAntimicrobianos são definidos como compostos naturais, sinté-ticos ou semi-sintéticos, cuja finalidade é prevenir ou tratar doenças infecciosas causadas por micro-organismos patogênicos, 1 tanto nos seres humanos como na medicina veterinária. Visto que não são totalmente metabolizados durante o uso terapêutico, os antimicrobianos estão presentes no esgoto doméstico principalmente como resultado da excreção humana. O uso de antimicrobianos na atividade pecuária contribui, também, para a sua introdução no meio ambiente, como resultado de processos de manufatura, disposição irregular ou excreção metabólica.2 Dessa forma, esses compostos são continuamente lançados no ambiente e, considerando sua característica recalcitrante de difícil remoção/degradação, são considerados pseudopersistentes.Existem aproximadamente onze diferentes classes de antimicrobianos, 3 que se diferenciam por sua estrutura química ou mecanismos de ação no tratamento específico de determinado patógeno. As quinolonas, antimicrobianos sintéticos, são eficientes no tratamento de infecções por bactérias Gram-positivas e Gram-negativas e são largamente empregadas tanto na medicina humana como veteriná-ria. Bactérias Gram-negativas são aquelas que possuem uma parede celular com poucas camadas de peptideoglicana e uma segunda membrana de lipopolissacarídeo. No processo de coloração, a lavagem com álcool rompe a camada externa de lipopolissacarídeo e o corante é removido por meio da camada de peptideoglicana. Consequentemente, as células Gram-negativas permanecem incolores até serem coradas com a safranina (segundo corante), adquirindo tonalidade rosa-avermelhada. Como exemplo, pode-se citar: Pseudomonas aeruginosa (causadora de infecções no aparelho pulmonar, urinário e respiratório), Escherichia coli (causadora de infecções urinárias) e Salmonella (causadora de intoxicações alimentares). As bactérias Gram-positivas, como por exemplo, a Streptococcus pneumoniae, possuem uma parede com mais camadas de peptideoglicana que as bactérias Gram-negativas. Empregando-se a coloração de Gram, apresentam-se com coloração púrpura quando fixadas com cristal violeta (primeiro corante), uma vez que essas bactérias retêm esse corante mesmo quando expostas ao álcool. 4,5 Dentre os principais riscos ...

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Drugs degrading photocatalytically: Kinetics and mechanisms of ofloxacin and atenolol removal on titania suspensions

Cited by 282 publications

References 33 publications

Photolysis and TiO2-catalysed degradation of diclofenac in surface and drinking water using circulating batch photoreactors

Photolysis and TiO2-catalysed degradation of diclofenac in surface and drinking water using circulating batch photoreactors

Impact of water quality on removal of carbamazepine in natural waters by N-doped TiO2 photo-catalytic thin film surfaces

Occurrence and Degradation of Quinolones by Advanced Oxidation Processes

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