Environmental Parameters and Denitrification Rates
Denitrification rates are generally low when the median grain size is greater than 2mm or less than 100 µm. This suggests that when grain size is small substrate supply may be limited and when grain sizes are larger carbon content is lower and scouring may have occurred; neither favor the establishment of biofilms or microniches and thus limits microbial activity.
The highest denitrification rates are generally associated with low C/N which are indicative of the availability of higher quality carbon. The relationship between denitrification rate and C/N is not tightly correlated, suggesting that carbon quality is not the primary or only controlling factor. High sediment hydraulic conductivity may enhance denitrification rates in sediments with similar carbon quality (e.g. Sugar Creek 4, green symbols).
