Electro-oxidation of diclofenac at boron doped diamond: Kinetics and mechanism

Abstract

a b s t r a c tDiclofenac is a common anti-inflammatory drug. Its electrochemical degradation at boron doped diamond electrode was investigated in aqueous solution. The degradation kinetics and the intermediate products were studied. Results showed that electro-oxidation was effective in inducing the degradation of diclofenac with 30 mg/L initial concentration, ensuring a mineralization degree of 72% after a 4 h treatment with the applied bias potential of 4.0 V. The effects of applied bias potential and addition of NaCl on diclofenac degradation were investigated. Different degradation mechanisms of diclofenac were involved at various applied bias potentials. With the addition of NaCl, some chlorination intermediates including dichlorodiclofenac were identified, which lead to the total organic carbon increase compared with the electrolysis process without NaCl addition at the reaction initial period. The main intermediates including 2,6-dichlorobenzenamine, 2,5-dihydroxybenzyl alcohol, and benzoic acid are identified at the time of 2 h. 1-(2,6-Dichlorocyclohexa-2,4-dienyl)indolin-2-one were also identified. These intermediates disappeared gradually with the extension of reaction time. Small molecular acids were identified finally. Based on these results, a degradation pathway of diclofenac was proposed.

Implementation of the method of electrochemical destruction during disposal of pharmaceutical glass waste

“…Studies conducted with the use of anodic oxidation showed complete destruction of diclofenac and beta-estradiol molecules, which were resistant to biochemical degradation, in solutions of these substances. Moreover, the process was more effective (less duration, higher degree of destruction) for diclofenac comparing with anodic oxidation, which was carried out using another anode and electrolytes [23].…”

Novel pilot scale continuous photocatalytic membrane reactor for removal of organic micropollutants from water

“…Considerations concerning the reactivity of the different sites on the DCF molecule and previous literature [26,27] suggest hydroxylation at dichroloaniline (4ˊ-OH-DCF) or phenylacetic acid moiety (5-OH-DCF) as the most favourable options. Analog hydroxylated derivatives on the aromatic rings have been identified in different irradiation or oxidation studies such as γ-radiolysis [28], ultrasound [29] and electro-oxidation [30] as well as in biotransformation studies [31]. On the other hand, OH-DCF isobaric species such as isomers 3ˊ-OH-DCF and 3-OH-DCF were also detected as TPs under vacuum ultraviolet photolysis [32], ozonation [33] and other photocatalytic studies [24].…”

Kanser İlaçları Atıksularının Elektrooksidasyon Prosesi ile Giderimi

“…Diklofenak etken maddesinin elektrooksidasyon ile gideriminin incelendiği çalışmada [14], siklik voltomogram sonuçlarına göre BKE elektrotun katalitik aktivitesi camsı karbon elektrottan daha yüksektir. Bor katkılı elmas ile 4 saatlik reaksiyon sonunda, diklofenak etken maddesinin neredeyse tamamı giderilmiştir.…”