Study of Influence Factors in the Evaluation of the Performance of a Photocatalytic Fibre Reactor (TiO2/SiO2) for the Removal of Organic Pollutants from Water

Abstract

The performance of a photocatalytic fibre reactor (UBE Chemical Europe), made of cartridges of fine particles of TiO2 dispersed within silicon fibres and irradiated by ultraviolet light, for the removal of organic pollutants from synthetic waters was evaluated. In the sensitivity analysis carried out, the factors catalytic surface area, fibre state, temperature and initial substrate concentration were studied using 4-chlorophenol as a test compound. The percentage of titanium in the fibre remained practically invariable after a series of experiments and cleaning procedures. Furthermore, the kinetics of removal of pyrene, phenol, 4-chlorophenol and bisphenol A (BPA) from water were evaluated by means of HPLC, UV-absorption and fluorescence techniques. Kinetic operational parameters were determined from a mathematical model proposed by Langmuir–Hinshelwood. Results show that catalytic surface, initial substrate concentration and temperature directly affect the degradation rate of organic compounds, whereas fibre state does not have a significant effect on that. It is proposed that removal of organic compounds from water mainly depends on the adsorption of the specific pollutant on the photocatalytic fibre and on the physical diffusion of the substrate towards the photocatalytic TiO2 active sites on the fibre, with the heterogeneous phase reaction prevailing over the homogeneous phase reaction.

Kinetics of photocatalytic degradation of organic compounds: a mini-review and new approach

“…Findings from various reports for a dilute solution revealed that PCD rate increases along with increasing C P,0 . 34,64,82,83 The recombination time of hole-electron pairs is very short (a few nanoseconds), 84 causing that photo-excited sites only react in a very narrow area. Therefore, a high C P,0 enhances the collision probability between organic molecules and photoexcited sites.…”

Solar Photocatalysis of A Pesticide in A Tubular Reactor on Titaniferous Sand as A New Semi-Conductor

“…It should also be noted that most of the studies of Photocatalysis on TiO 2 have been carried out using the suspension of fine particles of the photocatalyst in the solution to be treated. This operation thus has a limit because the fine particles of TiO 2 complicate the filtration once the solution has been treated [9]. As a result, photocatalytic suspension reactors are not compatible with the production of large-scale installations.…”

The Role of Dual Vacancies in TiO2 for Enhanced Photocatalytic Hydrogen Generation and Pollutants Removal

“…[6] However, TiO 2 has its drawbacks affecting reactivity, such as slow reaction rates, low quantum efficiency, and a narrow light absorption range. [7] Based on researches proposed various modification methods, including microelectronic structure modulation, [8] phase and morphology control, [9] crystal facet [10] and defect engineering, [11] construction of homojunction [12] and heterojunction, [13,14] many remarkable results have been achieved. Among them, defect engineering can modulate the electronic properties and photocatalytic reaction performance of TiO 2 by introducing vacancies, [15] which has been extensively investigated due to its low cost, simple preparation, and high efficiency.…”