Impact of hydrogen peroxide on nitrite formation during UV disinfection.
One concern with UV disinfection of water is the production of nitrite when polychromatic UV sources are utilized. Based on previous work, it was hypothesized that a small addition of hydrogen peroxide (H(2)O(2)) may be useful in controlling nitrite during UV disinfection. However, it was found that H(2)O(2) addition (5 or 10mg/L) during polychromatic UV irradiation of drinking water at doses used for disinfection significantly increases the levels of nitrite produced relative to solutions without H(2)O(2). Enhancement rates ranged from approximately 15% to 40% depending upon pH and H(2)O(2) concentration; the relative increase in the NO(2)(-) yield was greater at pH 6.5 than at pH 8.3. The observed effects are tentatively ascribed to a combination of enhanced superoxide production and increased hydroxyl radical scavenging when H(2)O(2) is added. These results indicate that H(2)O(2) cannot be used to control nitrite production during UV disinfection and that enhanced nitrite formation will occur if H(2)O(2) is added during UV water treatment to achieve advanced oxidation of contaminants.
Department of Civil and Environmental Engineering, School of Engineering, 121 Hudson Hall Engineering Bldg. Box 90287, Duke University, Durham, NC 27708, USA.
Charles M
CM
Sharpless
Margaret A
MA
Page
Karl G
KG
Linden
D004203:Disinfection / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D009573:Nitrites / Q000032:analysis*; D016877:Oxidants / Q000737:chemistry*; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
D009573:Nitrites; D016877:Oxidants; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide