THE FLORIDA STATE UNIVERSITY ARTS AND SCIENCES ...

Using this method the percent of loss of nitrogen due to denitrification is obtained for the
study areas in Jacksonville (Fl). While it was difficult to know the initial nitrate
concentrations we could assume the standard of 35mg/l/d or the highest nitrate
concentration value to be C0. As this is a very conservative estimate the result estimated
denitrification rate would be a minimum possible loss. Based on the above methodology
and assumptions we estimated 26 - 82% of nitrate removed in the Jacksonville area that
can be attributed to denitrification.
6.3. Use of isotopes to estimate the loss of Nitrogen due to
denitrification.
Between September 2009 and December 2010 samples were collected from three study
locations and an isotopic analysis is conducted at the Colorado Plateau Analytical
Laboratory, Arizona. The results are applied to the study sites
The data shows that denitrification is taking place in all the study areas, all of the regions
show an increase in δ 18 O as δ 15 N increases.
δδ 18 O
30.00
25.00
20.00
15.00
10.00
5.00
y = 0.4394x + 1.8219
R 2 = 0.9105
δ 18 O Vs. δ 15 N
0.00
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00
δ 15 N
Figure 6.2 δ 18 O vs. δ 15 N Eggleston Heights (April 2010).
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