The Case for LED-UVC as a Primary Disinfectant for Small Sustainable Drinking Water Systems

Abstract

High loads of natural organic matter (NOM) in source water increase levels of toxic byproducts during disinfection, including trihalomethanes (THMs) which are formed when NOM is chlorinated. This study explores the efficacy of using UVC-LED as a primary disinfectant, with lower concentrations of chlorine used as a secondary disinfectant. Both treatment trains with conventional chlorination and UV irradiation with low chlorination reduced total coliforms and E. Coli counts to less than 1 Cfu/100 ml. UV with low chlorination produced approximately 4.6 times less THMs compared to conventional chlorination.