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UDC 628.166.085

SMIRNOV A. D., Strelkov A. K., Tkachev Andrei

Revisiting the selection of wastewater disinfection technology

Summary

Environmental law enforcement in relation to discharging chlorine and organochlorine contaminants induces the use of advanced safe and efficient chlorine free methods of wastewater disinfection. The use of ultraviolet irradiation provides for meeting all the requirements imposed on the technology of wastewater disinfection eliminating any adverse impact on the environment. The use of this technology eliminates possible penalty charges for polluting the environment with chlorine and organochlorine contaminants. The economic comparison of two disinfection methods (the application of sodium hypochlorite and UV-irradiation) reveals significant operational benefit when introducing UV-disinfection. Annual savings of operational expenditures is 50% and more at the comparable capital expenditures. The advantages of UV-disinfection are as follows: efficiency in relation to all types of indicator and pathogenic microorganisms, whereas chlorine-containing chemicals do not often ensure fair efficiency in viruses and protozoa elimination; no by-products are generated; no adverse impact on the water bodies is produced (consequently, no penalties); no threat of overdosing; easy and simple control over the disinfection process; no need in dosing system and additional control systems; disinfection effect independence from fluctuations of effluents quality within the limits of the design parameters; minimum footprint; no additional facilities are needed (e. g., contact tank for dechlorination); possible retrofitting into the existing buildings or facilities, for example, in the process of wastewater treatment facilities upgrade and chlorination replacement; low operational expenditures (lamp replacing once in a year and a half – two years and energy saving). In this context switching to chlorine free disinfection technologies that eliminate the formation of organochlorine contaminants is a correct solution.

Key words

chlorination , disinfection , wastewater , dechlorination , ultraviolet irradiation , effluents charge