Table 14. Summary of findings from the
Table 15. Summary of findings from the fifth pesti-
fourth pesticide study--Effect of hot water
cide study--Effect of various treatments on LDPE
detergent wash and rinse on other polymers.
tubing.
Mean desorbed concentration (g/L)
a. Mean percent loss of analytes from test solution
due to sorption
after the following treatments
24-hr sorption*
Treatment
Lindane Heptachlor Aldrin Dieldrin
Material
Lindane Heptachlor Aldrin Dieldrin
Submerged wash* only
196
LD
2.84
LD
PVDF
2.1
75.0
5.0
53.4
Wash and methanol rinse 133
LD
1.80
LD
LDPE
71.4
>91.5
20.5
92.0
Wash and hexane rinse
123
LD
2.64
LD
P(VDF-HFP)
35.1
>83.8
23.7
82.6
†
11.8
LD
LD
LD
Wash and oven dry
MDL
0.74
0.84
0.55
0.85
b. Mean desorbed concentration (g/L)
LD = less than detection limit.
10-min sorb/10-min desorb*
* Hot water detergent wash and hot water rinse
Material
Lindane Heptachlor Aldrin Dieldrin
† ~117C for 24 hours
PVDF
LD
LD
LD
LD
LDPE
LD
LD
LD
LD
P(VDF-HFP)
LD
LD
LD
LD
Fifth pesticide study--Effect of various
decontamination treatments on LDPE
24-hr sorb/10-min desorb
The data from this study (Table 15) show that
Material
Lindane Heptachlor Aldrin Dieldrin
keeping the pieces of LDPE tubing submerged
PVDF
LD
LD
LD
LD
during the hot detergent wash and hot water
LDPE
LD
LD
LD
LD
rinse was not sufficient to remove these contami-
P(VDF-HFP)
LD
LD
LD
LD
nants. In addition, these data show that while
24-hr sorb/24-hr desorb
none of these procedures removed all the con-
Material
Lindane Heptachlor Aldrin Dieldrin
taminants from this material, the wash procedure
PVDF
LD
LD
LD
LD
followed by oven drying was by far the most ef-
LDPE
5.6
LD
1.7
LD
fective procedure. In this study, solvent rinsing
P(VDF-HFP)
LD
LD
LD
LD
significantly improved removal efficiency over
MDL
0.98
0.58
0.91
0.96
the washing procedure alone but was not nearly
* No measurements of analyte loss were made for 10 min.
as effective as oven drying (Table A11). It should
See Tables 10 and 11 for analyte losses at 10 min.
be noted that, with this method, residual concen-
LD = less than detection limit.
trations of the one remaining contaminant, lin-
dane, were approximately one-tenth of those
from the solvent treatments.
Fourth pesticide study--Effect of a hot
Apparently even large molecules such as pesti-
detergent wash on other polymers
cides are absorbed by LDPE, and thus oven dry-
After 24 hours' exposure, all three tubings
ing speeds diffusion of these molecules out of the
[LDPE, PVDF, P(VDF-HFP)] were highly sorptive
polymer.
of at least two of the pesticides (Table 14). Gener-
ally, LDPE was the most highly sorptive tubing
tested, and PVDF was the least sorptive. Parker
CONCLUSIONS
and Ranney (1996a) had similar results with re-
These studies show that if either permeable or
spect to sorption of VOCs and nitroaromatic com-
nonpermeable materials are not decontaminated,
pounds by these three tubings.
there will be significant carryover of both hydro-
Generally, these three materials were readily
philic and hydrophobic contaminants.
decontaminated by a hot detergent water wash
Table 16 summarizes the effectiveness of the
and hot DI water rinse. The exception was the
various decontamination procedures by listing
highly sorptive LDPE that was exposed to a 24-
the minimum treatment required to remove the
hour/24-hour sorption/desorption regime. We
contaminants. We found that any organic con-
thought that one reason why this tubing wasn't
taminant can be removed from the nonpermeable
effectively decontaminated by this procedure
stainless steel surfaces by using a hot detergent
may have been because the tubing pieces floated
wash and distilled water rinse. The permeable
on top of the cleaning solutions while the other
polymeric materials are much less readily decon-
materials sank to the bottom.
13
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