Uso de un reactor de placa plana (TiO₂/vidrio) para la degradación de 2,5-diclorofenol por fotocatálisis solar

The interest in solar photocatalysis degradation of non-biodegradable organic compounds in wastewater has raised due to its high efficiency and acceptable operation costs. The degradation of an aqueous 2,5-Dichlorophenol (2,5-DCP) solution with variable initial concentration (C₀ ≤ 98 mg/L) was performed by photolysis and solar photocatalysis, using a flat glass plate (1 m²) impregnated with TiO₂ synthetized by the sol-gel method, on a solar photo reactor. Two response variables (chemical oxygen demand and the 2,5-DCP concentration determined at 280 nm) were established by using three factors: slope angle (20° and 26°), flow rate (355 and 407 L/h) and two processes (photolysis and photocatalysis). The latter at high (ħv_prom = 847.4 W/m²) and low (ħv_prom = 453.6 W/m²) solar radiation intensity. The aqueous 2,5-DCP solution was recirculated over the glass plate for 60 min at laminar flow rate, and samples of the aqueous solution were taken every 5 min to determine the variables. Rate constants K₁ (min^-1) and K₂ (mol/L)^-1 of first and zero order reaction, respectively, were determined by considering elements originating on reactor dynamics in the evaluation of photocatalytic oxidation kinetics. Degradation percentages of 2,5-DCP over 98 % were achieved by solar photocatalysis.