HR: 0800h
AN: B51A-0192    [Abstracts]
TI: Potential Nitrous Oxide Emissions from Municipal Drinking Water
AU: * Anderson, D E
EM: deander@usgs.gov
AF: U.S. Geological Survey, WRD, M.S. 413, Bldg.53 Federal Center, Denver, CO 80225 United States
AU: Thienelt, T
EM: canyon62@gmx.de
AF: U.S. Geological Survey, WRD, M.S. 413, Bldg.53 Federal Center, Denver, CO 80225 United States
AU: Tindall, J
EM: jtindall@usgs.gov
AF: U.S. Geological Survey, WRD, M.S. 413, Bldg.53 Federal Center, Denver, CO 80225 United States
AU: McMahon, P
EM: pmcmahon@usgs.gov
AF: U.S. Geological Survey, WRD, M.S. 413, Bldg.53 Federal Center, Denver, CO 80225 United States
AB: Nitrous oxide (N₂O) is a potent greenhouse gas, having a global warming potential 280 times larger than carbon dioxide. Although the bulk of N₂O emissions appear to be related to agricultural activity, various industrial and transportation related emissions exist as well. This study reports the discovery of a new and significant source of potential N₂O emissions related to its presence in purified municipal water supplies worldwide. Multiple drinking water samples were obtained from 86 cities in the United States (US) and 44 cities in 16 countries in the Americas, Europe, Asia, and Africa. Samples ranged from 0.004 to 2μmol/L or the equivalent of 60% unsaturated to 200 times supersaturated with respect to ambient atmospheric concentration (320 ppb). Highest N₂O contents were from southern US cities. Suspecting nitrification as the cause for the presence of N₂O in drinking water, correlation statistics were calculated between N₂O concentration and city size, geographical location, mean annual temperature, nitrate, and ammonia concentrations for the total population of samples as well as subsets based on country, water purification method, and raw water source (ground, surface, combination). The highest correlation (r=0.66, p<0.05, N=73) found was between latitude and N₂O content for the subset group of large US cities using chloramines to purify water. Continuous year long sampling from a major US city indicated that variance in N₂O content is remarkably low through the year within a water supply district. The annual US emission, based on this preliminary analysis, is 8x10⁶ moles or 3.5X10⁸ g N₂O. Annual global emissions may be five times larger.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0493 Urban systems
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
SC: Biogeosciences [B]
MN: Fall Meeting 2005