Recognition of temperature distribution and light irradiation intensity toward degradation variation in photocatalytic water treatment

Photocatalytic degradation technology for water treatment has received broad attractions in recent years, producing many demonstrations focused on elucidating mechanisms and enhancing kinetics to scale degradation efficiency to higher levels. However, this ignores products variation depending on reaction parameters that are essential for practical applications of photocatalysis. Here, we undertake a critical analysis of light intensity and temperature in a novel photocatalytic slurry reactor utilizing an all-optical-fiber configuration for irradiation. The light irradiation intensity and temperature distribution in solution can be precisely controlled. The luminescent bacteria acute toxicity measurements of the intermediates referring to half-degradation stage and final products are performed in photocatalytic degradation process of Rhodamine B, possess a positive relationship with temperature and irradiation intensity. Conventional simulated solar light-driven configuration is subsequently constructed for comparison, exhibiting an obvious inhomogeneous spatial distribution of temperature increase. The toxicity of the final degraded products for the conventional reactor is higher than the optical fiber reactor. Our results indicate that the control and optimization of the temperature distribution and light irradiation intensity in photocatalytic process is of vital importance in the performance evaluation of photocatalytic water treatment.