UV紫外线杀菌器在水和废水处理中的应用英文原版研究论文_C01.pdf

1 Introduction Critical aspects for the wider application of ultraviolet (UV) light in drinking water treatment sometimes have been described, in spite of the success of the method as established in the field: • Absence of well-established and generally accepted design rules • Absence of a permanently active residual agent in the treated water • Suspicions of the possible photochemical formation of by-products • Possibility of revival–reactivation by repair mechanisms of irradiated organisms • Need for operational control of the permanent reliability of the technique The purpose of this publication is to analyze these concerns and to present extensive information (integrating both fundamental aspects and applications) on the currently available UV technologies applicable to water treatment. These tech- nologies include: • Lamp technologies available, criteria of evaluation, and choice of tech- nology • Fundamental principles applicable • Performance criteria for disinfection • Design criteria and methods • Outlook to synergistic use of UV + oxidants • Functional requirements and potential advantages and drawbacks of the technique 1.1 HISTORICAL: USE OF ULTRAVIOLET LIGHT IN DRINKING WATER TREATMENT UV radiation can be used for the improvement of drinking water quality. Presently, disinfection is the primary purpose of applying UV irradiation in water treatment. The technical method was introduced by drinking water facilities in the beginning of the twentieth century. © 2002 by CRC Press LLC The bactericidal effect of sunlight radiant energy was first reported by Downes and Blunt [1877]. However, the UV part of the sunlight that reaches the earth surface is merely confined to wavelengths higher than 290 nm. The so-called “Boston sunlight