Iranian Journal of Chemical Engineering (IJChE)

Abstract This study was conducted to decrease the concentration of acetic acid in wastewater of acetic acid plants through the photocatalytic oxidation method. This process employed commercial Titanium dioxide powder (TiO₂) as a photocatalyst, utilizing a UV lamp as the light source within a batch reactor system for advanced oxidation. Various experimental parameters were modified, including the concentration of acetic acid, the amount of catalyst, the volume of waste, temperature, and reaction time. The residual acid concentration and COD values were recorded as results of the process. The percentage of acetic acid remaining in the solution was determined by using a gas chromatography (G.C) device. Experiments were conducted with different volumes, from 200 ml to 35 ml, and utilized varying amounts of photocatalyst: 0.01 g, 0.005 g, 0.0025 g, and 0.001 g. Additionally, the experiments were carried out over two-time intervals of 2 hours and 5 hours. The wastewater concentration contained 3% by mass of acetic acid, and the average COD value was 13300. After experiments, it was found that the optimal conditions for removing acetic acid were a volume of 35 ml and 0.0025 g of catalyst used for 2 hours. In this condition, the percentage of acetic acid decreased from 3% to 0.2%, which is a 93% decrease, and the COD decreased from 13,300 to 2,800, which is a 79% decrease.

Abstract The nitrogen doped TiO2 as heterogeneous photocatalyst via sol-gel method were successfully synthesized. The physicochemical, morphological and textural characteristics of the obtained TiO2 samples were characterized by advanced analysis techniques. The photocatalytic activity of the samples were evaluated for degradation of 4-CP under solar irradiation. The as-synthesized photocatalysts were characterized with X-ray diffraction (XRD), surface area measurements (BET and BJH), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) and energy dispersive X-ray spectrum (EDX). The activities of as-prepared TiO2 photocatalysts were examined for the degradation of 4-Chlorophenol aqueous solution under solar irradiation in a photoreactor and photocatalytic degradation mechanism and pathway have been investigated. The results show that the 3% wt. N-doped TiO2 nanoparticles under conditions (solution pH of 4.0, catalyst loading of 2 g/L, initial 4-CP concentration of 10 mg/L, Time of 8 h) exhibits much higher photocatalytic degradation efficiency (91%) as compared with that of 5% wt. N-doped (83%), 1% wt. N-doped (71%), and pure TiO2 (35%).

Abstract The sintered glass filters with 90–150 μm porosity were coated with titanium oxide/silver composite. For deposition of titanium oxide, the filter was deep coated in the titanium oxide sole. Subsequently the solution of silver nitrate in methanol was used for silver deposition. The ultra violet (UV) radiation with 254 nm wave length was used for reducing silver ions to metallic silver. The prepared filters were characterized by X-ray diffraction and scanning electron microscopy. The photo-catalytic efficiency of TiO 2 and TiO 2/Ag coated sintered glass filters was investigated for photocatalytic decomposition of epichlorohydrin. The 67% of 1 and 20 mg/lit of epichlorohydrin solution in ethanol was decomposed by TiO 2 /Ag coated filter after 3 hours UVA radiations.