Use of an annular non‐sleeve photoreactor for photocatalytic dye degradation: Study of temperature and light intensity effects

In this article an annular non‐sleeve photoreactor (ANSP) is used to assess the TiO2/UV‐A advanced oxidation process, using the dye Acid Blue 9 (AB9) as model molecule. Within this particular configuration, the borosilicate glass or quartz sleeve that isolates lamp is removed. This fact allows the use of fluorescent BLB lamp to be in direct contact with suspension, which implies a variation of light intensity as a function of suspension temperature, surrounding the lamp. The variation of light intensity was evaluated in the range from 10 to 60°C, and the rates of dye degradation and chemical oxygen demand were also evaluated in the same interval of temperatures. Results showed that light intensity exhibits a proportional increment with temperature until a maximum at 40°C is achieved, then a slight decrease is observed. The degradation profiles of AB9 followed a pseudo first‐order kinetic model; whereas, chemical oxygen demand was defined by a pseudo zero‐order kinetic model. All kinetic constants exhibit a higher correlation with light intensity rather than temperature. The figure‐of‐merit electrical energy per order (EEO) was used to assess the electrical efficiency of the ANSP, and suggest an optimal operation temperature at 40°C. The sleeve removal is a practical application that could change the paradigm on photocatalytic reactor design, since wastewater treatment can be readily performed in a wide range of temperatures. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1083–1088, 2017