Abstract
Carbamazepine (CBZ) is a pharmaceutical compound recalcitrant to conventional wastewater treatment plants and widely detected in wastewater bodies. In the present study, advanced oxidation processes for carbamazepine removal are investigated, with particular regard to the degradation pathways of carbamazepine by photoelectrocatalysis and conventional photocatalysis. Photoelectrocatalysis was carried out onto TiO2 meshes obtained by Plasma Electrolytic Oxidation, a well-known technique in the field of industrial surface treatments, in view of an easy scale-up of the process. By photoelectrocatalysis, 99% of carbamazepine was removed in 55 min while only 65% removal was achieved by photolysis. The investigation of the transformation products (TPs) was carried out by means of UPLC-QTOF/MS/MS. Several new TPs were identified and accordingly reaction pathways were proposed. Above 80 min the transformation products disappear, probably forming organic acids of low-molecular weight as final degradation products. The results demonstrated that photoelectrocatalysis onto TiO2 meshes obtained by plasma electrolytic oxidation is a useful alternative to common advanced oxidation processes as wastewater tertiary treatment aimed at removing compounds of emerging concern.
Highlights
Organic micropollutants represent a group of contaminants of emerging concern (CECs) contained in the effluents of wastewater treatment plants
Despite the drawback consisting in the shielding effect of the mesh, the possibility of managing a supported catalyst, which does not need to be recovered with difficulty at the end of the treatment and it can be regenerated, makes electrochemical photocatalysis strongly advantageous if compared to conventional photocatalysis using commercial TiO2 powder (Degussa P25-TiO2 nanoparticle)
transformation products (TPs) were identified during photoelectrocatalysis, three of them
Summary
Organic micropollutants represent a group of contaminants of emerging concern (CECs) contained in the effluents of wastewater treatment plants. Free-suspending systems are inherently more efficient than the immobilized ones due to higher surface area [23,24] They suffer from severe disadvantages, such as catalyst loss and difficulty in recovery the catalyst at the end of the treatment, limiting their real application because of the poor quality of the treated effluent. Some of the authors recently reported that TiO2 films obtained by PEO outperform TiO2 nanotube arrays showing quantum yields higher than 90% in photon-to-electron conversion [32,38] They demonstrated that TiO2 films obtained by PEO are effective in water decolourization by photoelectrocatalysis [39] and that the catalysts can be successfully reused several times and regenerated if necessary [40].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
