Photocatalytic treatment of organic pollutants in a synthetic wastewater using UV light and combinations of TiO2, H2O2 and Fe(III)

Abstract

In this study, the photocatalytic treatment of an organic wastewater with/without phenolic compounds by means of ultraviolet irradiation, titanium dioxide and hydrogen peroxide was examined in an annular photoreactor. Specifically, the effect of initial total carbon concentration, catalyst loading and H 2 O 2 amount on the removal of total carbon was first examined in the case of a synthetic organic wastewater. The influence of partial carbon substitution by phenol, 2-chlorophenol, 2,4-discholophenol, trichlorophenol, and 4-nitrophenol on total carbon removal and target compounds’ conversion was studied keeping constant the initial organic carbon load. It was shown that the process applied was effective in treating the wastewater for initial total carbon 32 mg L -1 , 0.5 g L -1 TiO 2 , and 66.6 mg L -1 H 2 O 2 . Applying UV/TiO 2 and UV/H 2 O 2 , 58% and 53% total carbon removals were achieved, respectively, but combining TiO 2 and H 2 O 2 did not result in a better performance in the case of the synthetic wastewater without any phenolic compounds. In contrast, when a phenolic compound was added, the addition of H 2 O 2 was beneficial, eliminating the differences observed from one phenolic compound to another. The total carbon removals observed were lower than the corresponding final conversions of the target phenolic compounds. Finally, the electric energy per order values were calculated and found to range in 52–248 kWh/m 3 /order, being dependent from the process applied and the phenolic compound present in the wastewater.

The effect of caffeine, metronidazole, and ibuprofen on continuous flow activated sludge process

“…To evaluate the impact of pharmaceuticals on the efficiency of biological treatment of wastewater, the exact compositions of the synthetic wastewater was derived from the average concentration of actual municipal wastewaters 43,44 and was used in the previous works 10,45,46 . The average TC, TN, and ammonium concentrations in the final feed solution were 243.5 ± 49.8, 28.4 ± 5.7, and 11.4 ± 3.6 mg/L, respectively.…”

“…However, many pharmaceuticals are not biodegradable, and some of them exhibit recalcitrant properties 7 . Consequently, efficient pre‐treatment or post‐treatment systems, such as advanced oxidation processes, membrane bioreactors, and membrane filtration processes, have been employed to achieve complete removal of emerging pollutants in wastewaters 8–12 …”

Effect of Background Water Matrices on Pharmaceutical and Personal Care Product Removal by UV-LED/TiO2

“…For instance, the EEO values of 50-70 kW h m −3 were reported by Paredes et al [55] for degradation of gemfibrozil, carbamazepine, metoprolol, trimethoprim, and warfarin in secondary wastewater effluents using P25 and a low-pressure UV lamp (40 W). Poulopoulos et al [56] also reported the EEO values of 121-250 kW h m −3 for degradations of phenol, 2-chlorophenol, 2,4 dichlorophenol, 2,4,6, trichorophenol, and 4-nitrophenol in synthetic wastewater using P25 and a UV lamp (6 W).…”

Photocatalytic Porous Silica-Based Granular Media for Organic Pollutant Degradation in Industrial Waste-Streams

“…While various heterogeneous photocatalysts have been studied and utilized [20][21][22][23], titanium dioxide has received the most attention for organic contaminant degradation [24][25][26]. Titanium dioxide possesses photostability and low toxicity, making it a superior catalyst for organic pollutants [27][28][29].…”