Evaluation of low temperature adaptation for nitratation process: a review of production and attenuation of nitrite in an alluvial aquifer
Date
2012
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Abstract
Data obtained from the network of monitoring wells in the ammonium contaminated alluvial aquifer (Calgary, AB) was examined to describe the production and attenuation of nitrite during nitrification process. Since little is known about the nitrifiers' response to low temperatures in natural environments, the probable persistence of toxic nitrite is a concern to the health of the adjacent river (i.e., Bow River). It was suggested that low groundwater temperatures could cause a differential restraining effect between the performances of the two main groups of nitrifier bacteria; therefore, partial nitrification followed by persistence of nitrite will possibly occur. Although nitrite oxidizing bacteria (NOB) showed a minor lag in utilizing the produced nitrite with respect to ammonium oxidizing bacteria (AOB), the results indicated that nitrite levels did not exceeded 0.4 mg/L during groundwater nitrification. Accordingly, the rate of nitrifiers' activity at low temperatures showed to be similar and concurrent, and as a result partial nitrification was not the trend. Nevertheless, assessment of correlations revealed that temporal variation of low nitrite levels was primarily regulated by the transient oxygen levels, and nitrite attenuation was primarily controlled by nitratation. Collectively, this investigation concluded that the spatial and temporal distribution of nitrite was heterogeneous as the occurrence of nitrification was local and intermittent. In this respect, it was apparent that even under low temperatures with transient dissolved oxygen levels, which the latter is considered as an additional stress, both AOB and NOB can accordingly develop an effective syntrophy by their coupled physiological adaptability.
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Bibliography: p. 53-64
Some pages are in colour.
Some pages are in colour.
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Citation
Hashemi, R. (2012). Evaluation of low temperature adaptation for nitratation process: a review of production and attenuation of nitrite in an alluvial aquifer (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/4972