Feasibility Study of UV Disinfection for Agricultural Reuse of Secondary Level Effluent in Korea

Abstract A pilot study was performed to examine the feasibility of UV disinfection for agricultural reuse of reclaimed water. The effluent from the bio-filter of a 16-unit apartment was used as input to the flow-through type UV disinfection system, with average suspended solid (SS) and biological oxygen demand (BOD) concentrations of 3.4 and 5.9 mg/L, respectively, and a mean level of total coliforms in the range of 1.5 × 104 MPN/100 mL. UV disinfection was found to be effective, in that it reduced mean concentration of indicator microorganisms (total coliform [TC], fecal coliform [FC], and E. coli) to less than 100 MPN/100 mL within 60 s exposure using 17, 25, and 40 W lamps. The microorganisms often exceeded 200 MPN/100 mL with 17 and 25 W lamps, but were completely removed with 40 W lamp in one cylindrical chamber. Disinfection with two chambers in series demonstrated complete removal for all the experiments. About 30 mW·s/cm2 was thought to be adequate for the disinfection of secondary effluent to kee...