Accession Number : ADA112171

Title :   Effect of Soil Temperature and pH on Nitrification Kinetics in Soils Receiving a Low Level of Ammonium Enrichment.

Descriptive Note : Special rept.,


Personal Author(s) : Parker,L V ; Iskandar,I K ; Leggett,D C

PDF Url : ADA112171

Report Date : Dec 1981

Pagination or Media Count : 31

Abstract : Two soil samples from an on-going field study of land application of municipal wastewater were spiked with low levels of ammonium to determine the effect of temperature on nitrification kinetics. The concentrations of ammonium and nitrite-plus-nitrate, and the number of autotrophic ammonium and nitrite oxidizers were monitored periodically during the study. There was a lag period prior to nitrite-plus-nitrate production at all temperatures, and the length of this lag period was temperature-dependent, with the longest period occurring at the lowest temperature. The maximum rate of nitrification increased with temperature as expected. While nitrite-plus-nitrate production appeared logarithmic, suggesting a growing nitrifier population, the MPN counts of the nitrifiers did not exhibit logarithmic growth. To study the effect of soil pH on nitrification kinetics, soil samples from field plots having the same soil type but different pHs (4.5, 5.5, and 7.0) were spiked with low levels of ammonium and the rate of nitrite-plus-nitrate production was measured. The maximum rate of nitrification was greater at pH 5.5 than at 4.5. Unexpectedly rapid disappearance of ammonium, nitrite and nitrate, caused by immobilization, obscured the expected effects of pH on the nitrification rate at the highest pH.

Descriptors :   *Soils, *Nitrification, *Waste water, Ammonium compounds, pH factor, Temperature, Reaction kinetics, Rates, Nitrates, Nitrites, Removal, Oxidizers, Growth(General), Microorganisms, Waste treatment, Land use, Municipalities

Subject Categories : Soil Mechanics
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE