Performance analysis of ultraviolet water disinfection reactors using computational fluid dynamics simulation

Ultraviolet (UV) disinfection is an environmental-friendly technology for water treatment. However, design and operation of UV disinfection reactors is very difficult without a good model. In this work, motion trajectories of micro-organism particles in various UV water disinfection reactors with different shapes, sizes and lamp arrangements were simulated in the computational fluid dynamics (CFD) software: FLUENT, using the Monte-Carlo method and adopting a new methodology. The reactor performance based on micro-organism log reduction was analyzed under constant UV dosage. Effects of design and operating parameters on reactor performance were analyzed and discussed.

• A new methodology is proposed for CFD simulation of UV disinfection reactors. • Effects of design and operating parameters on reactor performance were analyzed. • Water flow rate, reactor size and shape had complex effects on reactor performance. • Reactor performance is correlated to particle motion in radial direction. • Multi-lamp reactors do not perform significantly better than single lamp reactors.