Influence of Water Quality on Nitrifier Regrowth...

As 2015 draws to a close, I wanted to share a recent accomplishment of mine: getting a paper published from my masters research.

Here are the details:

Title: Influence of Water Quality on Nitrifier Regrowth in Two Full-scale Drinking Water Distribution Systems

By: Daniel B. Scott, Michele I. Van Dyke, William B. Anderson, and Peter M. Huck

Journal: Canadian Journal of Microbiology


The potential for regrowth of nitrifying microorganisms was monitored in two full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a nine month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distributions systems. A culture-based presence/absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforces the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.

Keywords: ammonia-oxidizing, chloramine, distribution system, drinking water, nitrifier.


Another thing that I'm pleased to announce is that I'll be serving as a Member-at-Large on the board of Canoe Kayak New Brunswick. Follow them on Facebook to stay up-to-date; I may also blog about some of the projects and events of the association from time to time.

Finally, I've got one more post planned for 2015, which will be a review of the past year.