Pilot Test of a UV Odor Control System at the Ulu Pandan WRP, Singapore

Ultraviolet radiation (UV) has been widely used for water and air disinfection. However the application of UV for odor control has not experienced the same level of market acceptance. While there are some UV odor control products on the market, insufficient data are available to help us understand how UV oxidation works, and how best to apply this technology for municipal odor control. In this study we have evaluated UV oxidation of odors in the laboratory and applied what learned in a pilot UV reactor treating actual sewage odors at a wastewater treatment plant.The results show that UV lamps which generate 185 nm radiation can effectively oxidize hydrogen sulfide (H2S) and organic odors. The energy and number of lamps needed was found to be proportional to the mass rate of H2S and other odorous compounds. This makes UV most attractive for low concentrations, and as a polishing stage following biological or chemical odor control systems. To achieve high odor destruction efficiencies it was necessary to operate systems with some residual ozone at the exhaust. A means for destroying the residual ozone is important and requires further study.