Photocatalytic removal of phenol using titanium dioxide deposited on different substrates: Effect of inorganic oxidants

Enhanced removal of antibiotics in hospital wastewater by Fe–ZnO activated persulfate oxidation

“…When normalized to surface area of solids, the opposite trend can be, however, observed. At neutral pH, TiO 2 surface is positively charged (point of zero charge pH = 6.20), 46 and thus able to sorb effectively anionic ligands species. 9 In case of FLU (pKa = 6.5), more FLU adsorption to TiO 2 results in better photocatalytic activity (k app = 0.264 h -1 ) compared to Fe-ZnO (Fig.…”

Photocatalytic degradation of phenol by LaFeO3 nanocrystalline synthesized by gel combustion method via citric acid route

“…The photocatalytic reaction gives a different effect when the pH values of the solution are varies. This may due to the semiconductor's surface state of protonation, its isoelectric point, and the fact that dissociation of phenol are strongly pH dependent [17]. When pH < pKa value, phenol forms as a neutral species (C 6 H 5 OH), whereas when pH > pKa, the phenoxide ion (C 6 H 5 O − ) is form [18].…”

“…At 30 mg/L, less phenolic compounds may be adsorbed onto the surface of LaFeO 3 nanocrystalline, reducing the effectiveness of the process as the photocatalyst-contaminant mechanism mentioned before cannot be completed. While at 70 mg/L, generation of radicals may be halted as large number of phenolic molecules were adsorbed onto the catalysts' surfaces, minimizing the availability of vacant active sites for radicals' generation [17]. Furthermore, complete mineralization of phenol may not be achieved, instead, formation of phenolic intermediates took place thus increasing the total carbon formation, leading to greater light absorption when spectrophotometry analysis was carried out.…”

In situ Decolorization Monitoring of Textile Dyes for an Optimized UV-LED/TiO2 Reactor

“…Current photocatalytic processes in aqueous solutions involve different types of reactors [13][14][15][16][17][18][19][20][21][22], which can be classified in different groups according to their geometry (e.g., tubular or cylindrical, rectangular or square reactors, etc. ), liquid agitation techniques (e.g., continuous flow reactors, e.g., stirrer rotation) and lighting source including mainly low or medium pressure ultraviolet lamps [23][24][25][26][27], currently being replaced by LED lighting [28][29][30][31][32][33][34], which can reduce the size of the reactors, allowing the making of compact photo reactors known as mini reactors or micro reactors [35][36][37].…”