Disinfection fluence

Recently, several interesting applications of actinometers were published. For example, the fluence rate distribution Eq in mW cm at X of 253.7 nm in UV reactors can be determined by the iodide/iodate system (Stefan et al., 2001, Rahn, 1997), this being important for UV disinfection development. In connection with the development of novel incoherent excimer UV lamps several actinometric procedures have been applied to establish their radiant power efficiency, e.g. using 3,4-dimethoxynitrobenzene at X of 308 nm (Zhang et al., 1999), uridine at 222 nm (Zhang et al, 1997), hydrogen bromide (Pfeifer Roland et al., 1998), oxygen (Las-zlo et al, 1998) and methanol (Heit et al, 1998) at X of 172 nm. 

The various influences on the efficacy of UV disinfection are compiled in Fig. 9-1 (cf Malley Jr, 2000). Primarily, the efficacy of UV disinfection depends on the germicidal fluence Ho=EoXt which is the product of fluence rate Eq and the duration time t of the irradiation (often called UV dose , Chapter 2.1) (see Sommer et al., 1998). Other key factors include the hydraulics and hydrodynamics of the UV reactor (Kreft et al., 1986), its geometry (FIGAWA, 1998, Hoyer, 1996), the number and type of UV lamps required (Loge et al., 1996), their temperature profiles with respect to a maximum fluence rate Eq (in the case of LP Hg lamps, cf Fig. 4-8), the water quality and its variability such as UV absorbance/transmittance (Bolton et al., 2001, Sommer et al., 1997), the water matrix, e.g. nitrate concentration, its potential for quartz fouling by inorganic constituents particularly iron ions and hardness (cf Chapter 8-2), the turbidity, the particle content (total sus-... 

Wastewater, secondary effluent Dose distribution function Fluence rate distribution Modeling of flow and disinfection LP Hg lamps 24 - Point-source summation method Significance of reflection/refraction Steady two-dimensional model of flow and disinfection Coliforms Rummer (1990) Chiu et al. (1999) Bolton (2000) Lyn et al. (1999)... 

S. D. Trevor, C. Christian, and A. G. Graham, Hydraulic calibration and fluence determination of model ultraviolet disinfection system. Journal of Environmental Engineering 128(11), 1046-1055 (2002). 

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