UV disinfection

One way of implementing the UV disinfection process at existing activated sludge plants involves suspending the UV lights (in the form of low-pressure mercury arc UV lamps with associated reflectors) above the secondary clarifiers. The effluent is exposed to the UV radiation as it rises over the wire in a thin film. 

Mamane H (2008) Impact of particles on UV disinfection of water and wastewater effluents a review. Rev Chem Eng 24 67-157... 

A different concept is the idea of manufacturing at point of use rather than transporting materials. A simple and familiar example is the office water cooler. The majority that you see around use large bottles of water. These need to be transported and stored and the empty bottles recycled. More than 600 kT of bottled water were imported into the UK in 1999, creating a significant transport impact. The alternative is to chill and filter mains water on-site. The water needs to be filtered and purified to meet consumer perceptions and expectations. These systems use a mixture of purification techniques including advanced filters, UV-disinfection and silver-treated surfaces to give users the confidence they require. 

Lee, J., Zoh, K., and Ko, G. (2008). Inactivation and UV disinfection of murine norovirus with Ti02 under various environmental conditions. Appl. Environ. Microbiol. 74, 2111-2117. 

Apart from a few applications, such as UV disinfection and lacquer hardening, the intensity of UV radiation is well below that of visible light in ambient daylight or indoor lighting. A UV sensor must therefore be insensitive to visible light, otherwise the detection signal would easily be drowned out by the visible fraction of the radiation spectrum. Sensors that fulfill this requirement have a selective spectral sensitivity in the UV range. There are two important selectivities, known as visible-blindness and solar-blindness. 

Streptococcus faecalis uv disinfection, 8 652t Streptococcus pneumonia antibiotic resistant, 3 36 Streptocyanines, 20 505 Streptokinase, 5 175, 176... 

Physical disinfection of drinking water is mainly carried out through photodegradation by ultraviolet radiation (UV). Because many pharmaceuticals have chromophores that absorb UV wavelength, UV irradiation can lead to some transformation. Comparing to chemical oxidation, such as chlorination, UV disinfection has an advantage of minimizing the formation of DBPs [73]. However, at a... 

Advanced wastewater treatment techniques, for example oxidation processes, can achieve up to 100% removal for diclofenac [52,53], Reverse osmosis, activated carbon and ozonation have been shown to significantly reduce or eliminate antibiotics from wastewater effluents [32], The efficiency of two tertiary treatments, chlorination and UV disinfection, was compared and chlorination led to lower quantities of antibiotics [54],... 

Ultrasonic atomization applied to the removal of endocrine disrupting compounds (EDCs) from an aquatic environment Sono-sorption as a new technique for removing lead ions from an aqueous solution UV disinfection of water... 

Residual action to avoid nonregular or jagged disinfections (advantage compared to not persistent effect of UV disinfection systems)... 

Sommer, R., Haider, T., Cabaj, A., Pribil, W. and Lhotsky, M. (1998) Time dose reciprocity in UV disinfection of water. Water Sci. Technol. 38, 145-150. 

Design a UV disinfection system that will deliver a minimum design dose of 100 mJ/cm2. Assume for the purpose of this example that the following data apply ... 

Configure the UV disinfection system. Typically, 2, 4, 8, or 16 lamps per module are available. For an 8-lamp module, eight modules are required per bank for a total of 64 lamps per bank. 

Both of these hydraulic loading rates fall within the acceptable range for the UV disinfection system provided by the manufacturer. 

Short reviews of the recent research activities into UV disinfection of water and air and of the UV treatment techniques of polluted air are enriched by the description and discussion of several selected examples of published industrial applications. Many questions related to the selection of UV processes will be answered and common pitfalls referring to UV applications addressed. 

In the United States and Canada even biologically pretreated municipal waste waters (secondary sewage effluents) are usually UV disinfected by passing through huge irradiation channels before they are drained into the surface water and released into natural cycles. It has been shown that UV irradiation is a power-... 

All of the facts mentioned above and the observation that several photochemical AOTs for water and air remediation have been successfully commercialized during recent years, justify a comprehensive description of photochemically driven advanced oxidation processes for water and air treatment in this book, which includes a brief description of UV disinfection techniques. 

Ho C-F H, Pitt P, Mamais D, Chiu C, Jolis D (1998) Evaluation of UV Disinfection Systems for Large-scale Secondary Effluent, Water Environ. Res. 70, No. 6 1142— 1150. 

The selection of a treatment process for industrial and municipal wastewater and for industrial coohng, purging or product waters depends mainly on the specific use and the desired water quality. If necessary, it should include UV disinfection, UV detoxification, or UV purification. On the other hand, the production of pure and ultra pure water for pharmaceutical purposes or of cleaning water for computer chip manufacturing industries requires disinfection and total mineralization of the organic matter content (Bendlin, 1995). 

The special features of UV treatment technologies of water and air that are favored by manufacturers, researchers and developers are collected in Tab. 2-1 (cf FIGAWA, 1997, Prengle Jr et al., 1996, Freeman and Harris, 1995, von Sonntag, 1995, Meyer and Fischer, 1994). From this table it is evident that a remarkable difference in the numerical handhng of UV disinfection and photo-initiated oxidation techniques ex-... 

To avoid any confusion it must be stressed that several authors use the term UV dose in UV disinfection literature (Leuker, 1999, Chiu et ah, 1999) instead of... 

Henri et al. Large scale UV disinfection of water and pilot plant installation von Sonntag (1987) ... 

Smith First full-scale UV disinfection of water in the USA Rice (2001) ... 

Oliver and Carey UV disinfection as an alternative to chlorination Oliver and Carey (1976)... 

---