Enhanced dye wastewater degradation efficiency using a flowing aqueous film photoelectrocatalytic reactor

Abstract

A TiO₂/Ti flowing aqueous film photoelectrocatalytic (PEC) reactor was developed and successfully applied to degrade Reactive Brilliant Blue X-BR (RBB) and textile effluent. The high treatment efficiency achieved by flowing aqueous film PEC process was attributed to the enhanced light utilization resulting from the significantly reduced path length (down to average approximately 78 μ m level). The dye wastewater was kept circulating (7.7 L h⁻¹) during the experiments to continuously refresh the aqueous film on the TiO₂/Ti photoanode and promote the mass transfer of the target pollutants and the degradation products in the bulk solution. Using a 20–150 mg L⁻¹RBB solution as the model system, flowing aqueous film PEC removed color by 83–44% in one hour, much higher than the 75–12% by conventional PEC. Results also suggested that flowing aqueous film PEC was particularly superior to conventional PEC for treatment of a high concentration solution. The feasibility of the TiO₂/Ti flowing aqueous film PEC reactor was investigated by treating industrial textile effluent. A color and total organic carbon (TOC) removal of 75% and 50% respectively, were achieved in two hours. Thus, in the present study, we propose a new concept for the design of a PEC reactor applicable to industrial wastewater treatment.

Keywords:

• Flowing aqueous film photoelectrocatalytic reactor
• TiO₂/Ti electrode
• Reactive Brilliant Blue X-BR
• textile effluent

Acknowledgments

Financial support from the Natural Science Foundation of China (Project No.20477026) is gratefully acknowledged.

Notes

^a In 1 cm quartz cell.

^b In 4 cm quartz cell.