A Study of the Photocatalytic Oxidation of Humic Acid on Anatase and Mixed-phase Anatase–Rutile TiO2 Nanoparticles

Abstract

In this study, slurry photocatalytic oxidation process was investigated for natural organic matter removal from aqueous humic acid solutions by using different titanium dioxide (TiO 2 ) under UV-A irradiation. Bench scale experimental studies were conducted at different humic acid concentration at the range of 10-50 mg/L and different pH. Anatase and mixedphase anatase-rutile TiO 2 nano particles used in the photocatalytic reactor. The results were evaluated in terms of the parameters that are specific to organic matter content such as dissolved organic carbon concentration, ultraviolet absorbance at 254 nm (UV 254 ), specific ultaviolet absorbance at 254 nm, and color (VIS 400 ). It was observed that increasing humic acid concentration decreases photocatalytic degradation efficiency. The reactivity of the mixedphase anatase-rutile (Degussa P-25) TiO 2 was greater than individual anatase particles and the highest efficiency was observed at pH 3 for anatase TiO 2 .

A novel approach of preparing TiO2 films at low temperature and its application in photocatalytic degradation of methyl orange

“…In 1976, Carey et al [2] found that after irradiated by UV light, TiO 2 was capable to catalyze the dechloridization of polychlorobiphenyl (a group of organic pollutants) in water, which initiated the application of the photocatalytic technology on environmental remediation. In the past decades, TiO 2 has been applied in decomposition and mineralization of some persistent organic pollutants (POPs) such as phenols, chlorophenols, pestcides, herbicides, benzenes, humic acids and others [3][4][5][6][7], as well as water and air purification [8][9][10][11][12].…”

Optimization of horizontal photocatalytic reactor for decolorization of methylene blue in water

“…Consequently, the optimal catalyst concentration for decolorizing MB in our case study was found to be 1 g/L of P25-TiO 2 at the constant suspension flow rate of 460 mL/min using the pr-PTC. From the previous literatures on the investigation of photocatalytic water treatment in continuous flowing system, the catalyst concentrations were mostly used in the range of 0.04-0.5 g/L and not more than 2.0 g/L, as shown in Table 3 and other researches [36][37][38][39][40][41][42][43][44][45][46][47]. The optimum of P25-TiO 2 concentrations possibly depends on the suspension flow rate used in the independent system for purifying water.…”

Electrode Materials a Key Factor to Improve Soil Electroremediation

“…Although, other authors (Yigit & Inan, 2009) have provided evidence on how a mixture anatase-rutile provides a higher efficiency in humic acid mineralization.…”