Applications of UV Unit for Aqueous-Phase Disinfection

Any ideal UV disinfection system should provide sufficient dose to kill pathogens in water and wastewater. Both closed and open UV systems can be used as shown in Figs. 7 and 8. Closed channel UV system is often used in drinking water disinfection, while open channel UV system is always adopted for wastewater disinfection. No matter 

The advantages of UV disinfection over chemical disinfectants include  

More effective on some pathogens such as Cryptosporidium than chlorine. 

In the chlorine disinfection, reducing agents like sulfur dioxide must be used to eliminate the discharged toxic chlorine. Besides, special considerations must be applied to control natural organic matter (NOM) in water source or to reduce the potential by-product precursors after the disinfection unit. These concerns however become less obvious when UV radiation is used for disinfection of water. 

The geometry of UV lamp arrangement, the water absorbance, the characteristics of the lamp, and the turbulence of water flow can influence the disinfection efficiency. Consequently, the elimination of dead area and the maintenance of uniform flow should be considered in the design. 

---