Disinfection of secondary effluents using tin oxide anodes.
Direct current applied to a tin oxide anode submersed in water has the potential to generate hydroxyl radicals, a strong chemical oxidant. Tin oxide anode systems, which may represent a viable alternative disinfectant, were investigated for the disinfection of secondary effluents. Coliform bacteria in the effluent were effectively inactivated in a bench-scale tin oxide disinfection system. The number of anodes in the tin oxide disinfection system influenced the steady-state concentration of hydroxyl radicals and, consequently, the contact time necessary to achieve a specified dose. The life expectancy of the anodes was greater than 30 days and no appreciable loss of tin was observed over a 5-day period. A preliminary estimate of the capital and operating costs of a pilot- or full-scale tin oxide disinfection system designed to meet a discharge requirement of 23 most probable number/100 mL at a 3 785-m3/d (1-mgd) facility was comparable to UV and chlorination/dechlorination facilities. Based on this preliminary assessment, tin oxide disinfection systems are a promising alternative disinfectant for secondary effluents.
Department of Civil and Environmental Engineering, University of California at Davis, 95616, USA. fjloge@ucdavis.edu
Frank J
FJ
Loge
Trevor
T
Inouye
Richard J
RJ
Watts
D004202:Disinfectants / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D004755:Enterobacteriaceae / Q000254:growth & development; D017971:Tin Compounds / Q000378:metabolism*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
D004202:Disinfectants; D017971:Tin Compounds