Spiramycin photocatalysis under artificial UV radiation and natural sunlight

Photocatalytic processes in the presence of titanium dioxide, operating in UVA radiations, present great interest for degradation of hazardous organic contaminants. The objective of the work presented is to evaluate the performance of spiramycin (SPM) photocatalytic degradation in TiO2 aqueous suspension using solar irradiation and artificial UVA (365 nm) light. SPM degradation and mineralization were assessed to establish the feasibility of both treatments. To achieve this study, the effect of the initial SPM concentration and the catalyst concentration on the photocatalytic degradation were optimized. Photocatalysis removal of different SPM concentrations (10, 20, 40 mg L-1) was tested using 0.25 g L-1 of TiO2. SPM degradation percentage achieved after 360 min was 95.6% under both types of radiation (solar and artificial light). However, the mineralization percentage were 89.2 and 87.8% in solar and laboratory conditions, respectively. The kinetics followed the first-order and the reaction rate was well fitted with Langmuir-Hinshelwood model. Solar photocatalysis has demonstrated to be useful for the removal of SPM. The UV/TiO2 photocatalysis process can be suggested for the SPM degradation in aqueous solution.