Degradation of diclofenac by TiO2 photocatalysis: UV absorbance kinetics and process evaluation through a set of toxicity bioassays

Rizzo, Luigi; Meriç, Süreyya; Kassinos, Despo; Guida, Marco; Russo, Francesca; Belgıorno, Vincenzo

doi:10.1016/j.watres.2008.11.040

Cited by 260 publications

(116 citation statements)

References 30 publications

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“…A maximum extent of 2.2 AE 0.8 to 10.8 AE 1.6 % was observed for DCF at the end of the adsorption period. This low adsorption is in accordance to dark adsorption studies of DCF on TiO 2 as reported by Rizzo et al [32] Photophysical properties of DCF A comparison of the absorption spectrum of DCF and the radiant flux distribution of the TQ-150 lamp is shown in Fig. 3.…”

Section: Resultssupporting

confidence: 88%

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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: Resultssupporting

confidence: 88%

“…[13,[30][31][32][33][34] Existing studies describing photolysis either in the laboratory or in the natural environment using sunlight have reported direct photolysis as the main depletion mechanism for DCF. Discrepancies have, however, arisen between studies on the effect of artificial UV light on DCF phototransformations.…”

Section: Introductionmentioning

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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“…Diclofenac is rapidly decomposed by natural sunlight to many products. But some of the photoproducts show much higher toxicity than the parent drug 4 , and since they are not mineralized by solar irradiation they stay in the environment as persistent pollutants 5 . Therefore, to solve all of the above mentioned problems, it is important to fi nd an effi cient way for the removal of diclofenac and other NSAIDs from water.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Performance of Hybrid Photolysis-DCMD and Photocatalysis-DCMD Systems Utilizing UV-C Radiation for Removal of Diclofenac Sodium Salt From Water

Mozia

Darowna

Przepiórski

et al. 2013

Polish Journal of Chemical Technology

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The removal of a non-steroidal anti-infl ammatory drug (NSAID) diclofenac sodium salt (DCF, C 14 H 10 Cl 2 NNaO 2 ) from water in two hybrid systems coupling photolysis or photocatalysis with direct contact membrane distillation (DCMD) is presented. A UV-C germicidal lamp was used as a source of irradiation. The initial concentration of DCF was in the range of 0.005-0.15 mmol/dm 3 and the TiO 2 Aeroxide® P25 loading (hybrid photocatalysis-DCMD) ranged from 0.05 to 0.4 g/dm 3 . Regardless of the applied hybrid system and the initial concentration of DCF, the model drug was completely decomposed within 4 h of irradiation or less. Mineralization was less effi cient than photodecomposition. In case of the hybrid photolysis-DCMD process the effi ciency of TOC degradation after 5 h of irradiation ranged from 27.3-48.7% depending on the DCF initial concentration. The addition of TiO 2 allowed to improve the effi ciency of TOC removal. The highest degradation rate was obtained at 0.3 gTiO 2 /dm 3 . During the process conducted with the lowest DCF initial concentrations (0.005-0.025 mmol/dm 3 ) a complete mineralization was obtained. However, when higher initial amounts of DCF were used (0.05-0.15 mmol/dm 3 ), the effi ciency of TOC degradation was in the range of 82.5-85%. The quality of distillate was high regardless of the system: DCF was not detected, TOC concentration did not exceeded 0.7 mg/dm 3 (1.9 mg/dm 3 in permeate) and conductivity was lower than 1.6 μS/cm.

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“…An exhaustive study on the heterogeneous photocatalytic degradation of DCF over TiO 2 in presence of UV-A irradiation was done with emphasis on the effect of catalyst type, initial DCF concentrations, photocatalyst loading and H 2 O 2 as an additional oxidant (Achilleos et al 2010;Rizzo et al 2009). Also, Martinez et al (2011) investigated the influences of operational parameters as the type of photocatalyst, presence of dissolved O 2 or addition of H 2 O 2 as co-oxidant, which affects DCF photocatalytic degradation.…”

Section: Introductionmentioning

confidence: 99%

Aqueous degradation kinetics of pharmaceutical drug diclofenac by photocatalysis using nanostructured titania–zirconia composite catalyst

Das

Barodia

Sengupta

et al. 2014

Int. J. Environ. Sci. Technol.

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Diclofenac (DCF) is an anti-inflammatory pharmaceutical drug, and its presence in a trace amount in waste water makes severe environmental pollution. The degradation of DCF was investigated by a photocatalytic process in presence of ultra violet irradiation at room temperature using titania and titania-zirconia nanocomposite catalysts in a batch reactor. The composite catalyst was prepared by sol-gel method and characterized by X-ray diffraction, transmission electron microscopy as well as BET surface area analyzer. The effect of various process parameters such as catalyst loading, initial concentration of DCF and pH of the experimental solution was observed on the degradation of DCF. The titania-zirconia nanocomposites exhibited reasonably higher photocatalytic activity than that of anatase form of titania without zirconia. The maximum removal of DCF of about 92.41 % was achieved using Zr/Ti mass ratio of 11.8 wt% composite catalyst. A rate equation was proposed for the degradation of DCF using the composite catalyst. The values of rate constant (k c ) and adsorption equilibrium constant (K 1 ) were found to vary with the catalyst content in the reaction mixture.

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Degradation of diclofenac by TiO2 photocatalysis: UV absorbance kinetics and process evaluation through a set of toxicity bioassays

Cited by 260 publications

References 30 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

Evaluation of Performance of Hybrid Photolysis-DCMD and Photocatalysis-DCMD Systems Utilizing UV-C Radiation for Removal of Diclofenac Sodium Salt From Water

Aqueous degradation kinetics of pharmaceutical drug diclofenac by photocatalysis using nanostructured titania–zirconia composite catalyst

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