AWWA WQTC69273

In recent years, ultraviolet (UV) technology for drinking water disinfection has experienced rapid growth in North America and Europe driven by the needs of disinfection byproduct reduction and control of emerging pathogens, such as Cryptosporidium, that are resistant to chlorination. Tsinghua University did some work based on pilot scale UV system in Dongguan. The objective of this study was to evaluate the efficacy of UV systems for drinking water under pilot-scale conditions (continuous flow system) and compared with the collimated beam results using the same water quality. The experimental results showed that: UV was effective against E. coli and TBC. B. subtilis, and MS2 was more UV-resistant especially when UVT was below 90%; the inactivation of microorganisms by UV could be described with first-order kinetics using fluence-inactivation data from laboratory studies in CB tests for a certain fluence range, no inactivation at low fluences (shoulder) and no further increase of inactivation at higher fluences (tailing) was observed for some challenge micro-organisms; water quality and UV sensitivity of microorganism influenced the inactivation rate; for the daily monitor results of 13000 hours, UV could be a stable disinfectant for total coliform and TBC; and, the lamp intensity of the online monitor showed that the lamp efficiency decay was limited within the first 12000 hours. Includes 10 references, tables, figures.