الفهرس 
Catalytic wet peroxide oxidationOnly 14 pages are availabe for public view
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Abstract
A novel photocatalytic reactor was designed for the extended reuse of W-TiO2 catalyst. The reactor successfully degraded sulfamethazine (SMZ) antibiotics. The degradation of carbofuran (CBF) pesticide by a robustly dual catalyst Ti-substituted LaFeO3 was also investigated. The W-TiO2 catalyst was attached to stainless steel plates using polysiloxane. An experimental design using the Box-Behnken method indicated an initial SMZ concentration of 17.42 mg/L, a 300 mL/min flow rate, and a pH of 4.0 is the optimal operating parameters.
The photocatalysts’ extended reuse for five consecutive runs obtained an SMZ degradation of 97.7%, 97.6%, 96.2%, 95.1%, and 90.34% in the same order. Different radical scavengers were used to investigate the influence of radical oxidative species. The experiments indicated that hydroxyl radicals, holes, and superoxide radicals have contributed to the photocatalytic oxidation of SMZ. A possible pathway for SMZ degradation was proposed based on the identified transformation products by tandem mass spectrometry. In general, the results showed a high prospect of application of our reactor design due to the simple operation, reusability, and high efficiency.
Carbofuran pesticide was degraded using a robustly reusable dual photo-CWPO/photocatalytic Ti-substituted LaFeO3 catalyst. The central composite experimental design was applied and indicated that initial CBF concentration of 7.0 mg/L, initial catalyst concentration of 700 mg/L, initial hydrogen peroxide concentration of 480 mg/L, and pH 3.0 are the optimal operating parameters. Under optimum conditions, CBF removal was 90.6% after 180 min of reaction. The TOC was reduced from 4.5 mg/L to 2.38 mg/L after 180. Reusability tests for 5 repetitive cycles under the optimum conditions indicated a final removal efficiency of 90.6%, 88.4%, 79%, 68.6%, and 64.1%, respectively. Moreover, ROS inhibitors were applied to study the role of different radical species in CBF degradation. The results showed that hydroxyl radicals were the principal contributor to CBF degradation. A possible degradation pathway for CBF was proposed according to the identified transformation products.