100
was similar, with the rate of change being great-
est for TNB. Both analytes were stable for the
first seven days, but substantial losses were ob-
served by day 14 (Fig. 14). This behavior is some-
80
Groundwaters
what different from that found in the fortified
Connecticut River water, where major losses of
these two analytes were observed by day 3 (Fig.
60
15). The behavior in both matrices is consistent
with microbiological transformation being the
major loss mechanism for these compounds.
40
For Connecticut River water, a large population
Connecticut River
of aerobic microorganisms is undoubtedly
Water
present initially that requires little or no accli-
20
mation time before being capable of transform-
MW Groundwater
PT Groundwater
ing these compounds. In the groundwater, the
TR Groundwater
Connecticut River Water
initial population of aerobic microorganisms is
probably many orders of magnitude lower, and
0
20
40
60
it appears that several days are required for the
Storage Time (days)
populations to increase sufficiently to result in
Figure 15. Losses of TNT in unacidified groundwaters and
significant analyte losses.
Connecticut River water samples as a function of storage time.
The behavior of tetryl in the unacidified
groundwaters is somewhat different from TNB
60
and TNT. For tetryl, a small loss in all three
groundwaters was observed by day 3, with sub-
stantial loss for two of the three groundwaters
by day 7 (Table 8). This behavior is consistent
with earlier research showing that losses of tetryl
40
can occur by hydrolysis as well as microbio-
logical transformation (Kayser et al. 1984,
Jenkins 1994).
The behavior of 4ADNT in these fortified
groundwaters is similar to that observed in for-
tified Connecticut River water for acidified
20
samples, but somewhat different for unacidified
controls. For unacidified samples, no losses of
MW Groundwater
PT Groundwater
4ADNT were observed over the 64-day study.
TR Groundwater
Connecticut River Water
For the acidified samples, substantial losses
were observed for all three groundwaters that
0
amounted to 29%, 44%, and 47% for the TR, PT,
20
40
60
Storage Time (days)
and MW groundwaters, respectively, after 64
Figure 16. Losses of 4ADNT in acidified groundwaters and
days (Fig. 16). Percent loss of 4ADNT in the TR
Connecticut River water samples as a function of storage time.
groundwater was similar to that found in the
Connecticut River water, and losses in the other
two matrices were greater.
Acidification to pH 2 eliminated losses of TNB
and TNT over the entire 64-day study for all three
Evaluation of acidification using
fortified groundwaters. Acidification also elimi-
field-contaminated groundwater
nated losses of tetryl for two of the three ground-
Since chemical preservation using acidification
waters over the 64-day period, but some loss of
to pH 2 with sodium bisulfate looked promising,
tetryl was observed after day 28 for tetryl in ma-
this technique was further evaluated with 36
trix no. 3 (Table 8). Substantial losses of tetryl,
groundwater samples from monitoring wells at
TNB, and TNT were observed in all of the unacidi-
the Naval Surface Warfare Center (NSWC) in
fied samples, however. The pattern of TNB and
Crane, Indiana. At each well, two water samples
TNT loss in the three unacidified groundwaters
were collected in 125-mL glass bottles. A 0.2-g
17
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