title: Factors affecting nitrification in situ in a heated stream.
abstract: Nitrification, previously shown to occur in the stream under study, ensued only when the stream received heated (28 degree C or above) discharges and was negligible when water temperatures were 17 degree C or lower. The most probable number os ammonium oxidizer in stream bed sediments exceeded intrite oxidizers by ratios of 43:1 to 1,113:1, and the average rate of ammonium oxidation in this stream, 0.50 mg of NH4-N/liter per h exceeded the rate of nitrite oxidation, 0.29 mg of NO2-N/liter per h, resulting in an accumulation of nitrite. Nitrification rates were influenced by the dissolved oxygen concentration, increasing during daylight hours and exhibiting maximum rates during the summer months.
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D005618:Fresh Water; D006358:Hot Temperature; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D012621:Seasons; D013472:Sunlight; D014871:Water Microbiology
chemical_list: D009566:Nitrates; D009573:Nitrites; D000641:Ammonia