1
1
Supplemental Data
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S1- Time to sorptive equilibrium
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Experimental Parameters
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Particulate matter and wastewater were collected on 7/26/11. They were combined to produce a solution
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with a suspended solids concentration of 19 mg/L. 15 ng of pyrethroids were added to 30 mL aliquots of
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particle solution (Ctotal = 500 ng/L). Duplicate samples were extracted at 30, 90, 150, and 1680 min. Solid
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phase microextraction (SPME) and gas-chromatography negative chemical ionization mass spectrometry
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(GC-NCI-MS) were performed as described in the Methods section.
9
10
Figure S1- Time to sorptive equilibrium. Error bars represent the range between duplicates.
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Excel 2007 was used to test the significance of a linear slope. It was not significant (α=0.05) in all cases.
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An equilibration time of 16 hours (960 minutes) was selected. Rates of permethrin sorption to wastewater
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particles were assumed to be similar to those for the three pyrethroids tested.
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2
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S2- Time to equilibrium between pyrethroid and SPME fiber
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Experimental parameters
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Pyrethroid was added to 30 mL MilliQ water (Millipore) to obtain a concentration of 20 ng/L. Samples
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were extracted for 10, 20, 30, 60, 90, and 150 minutes and analyzed as described in Methods Section.
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After completion of SPME analysis the GC-NCI-MS was reverted back to liquid analysis and standards
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were injected to quantify pg on column.
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22
Figure S2: Fiber uptake of lambda-cyhalothrin. Error bars represent the standard deviation between
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samples.
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25
26
27
28
29
30
3
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S3- Effluent Water Quality Parameters
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Whole Effluent Water Qualitya
UC Davis Measurement
University of Maryland’s Horn Point
Laboratory
Total
Volatile
Total
Particulate
Dissolved
Sampling
Suspended
Suspended
Suspended
Organic Carbon Organic Carbon
Event
Solids (TSS)
Solids (VSS)b
Solids
(POC)
(DOC)
(TSS)
9.7
NM
11.5
6.9
13.2
21 Nov (R)
5.4
NM
3.8
2.9
13.1
16 Feb (R)
4.0
3.1
2.7
2.4
10.8
19 Apr
7.3
5.7
5.4
2.7
10.9
26 Jul
9.3
7.1
7.7
3.3
11.9
20 Sep
14.3
12.6
5.4
4.6
11.1
21 Jan (R)
a
All values are in mg/L
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b
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Table S3- Water quality parameters for whole effluent. UC Davis measurements were made from grab
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samples collected during 24-hr sampling event. University of Maryland’s Horn Point measurements were
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made from 24-hr composite effluent samples.
NM indicates that value was not measured
4
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S4- Particle size distribution (PSD) of reconstituted wastewater sample
0.6
0.5
0.4
0.3
DFE
0.2
Reconsituted Sample
0.1
0
0.5
0.63
0.794
1
1.414
2
2.828
4
4.757
5.657
6.727
8
11.31
16
20
Fraction of total particle count
PSD Comparison
Particle Size Bin (um)
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39
Figure S4- Comparison of the particle size distribution between the whole effluent (DFE) and the
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reconstituted sample
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42
43
44
45
46
47
48
49
5
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S5- Particle fractionation by lab centrifugation
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52
53
Figure S5- Pyrethroid concentration of each treatment by sampling event. A star indicates there was a
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significant difference between DFE and <0.8 µm means at α=0.05. Error bars show the standard deviation
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between replicate samples.
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6
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S6- PSD in particle fractionation
Particle Fractionation
Particle Counts
2500000
2000000
1500000
Whole Effluent
1000000
<2.6 um
500000
<0.8 um
0.5
0.63
0.794
1
1.414
2
2.828
4
4.757
5.657
6.727
8
11.31
16
20
0
Particle Size Bins (um)
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Figure S6- Particle size distribution of each centrifuge treatment. Jan event is shown and is
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representative of other sampling dates.
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7
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S7- Number of replicates used in Kd single point calculation
21 Nov (R)
16 Feb (R)
19 Apr
26 Jul
20 Sep
21 Jan (R)
Number of replicates used in Kd calculation
Bifenthrin λ-Cyhalothrin Cypermethrin
6
6
6
12
12
12
9
12
12
10
12
12
11
12
12
12
12
12
Permethrin
6
10
8
9
12
11
63
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Table S7- Number of replicates used for Kd calculation. Replicates were only dropped if the SPME
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measurement was below the reported limit of detection.
8
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S8- Comparison of SPME pre-treatment methods
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Experimental parameters
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Wastewater particle solution was prepared at a TSS concentration of 20 mg/L. Two 30 mL aliquots of
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particle solution were prepared for direct SPME analysis and are referred to as “regular”. Six 36-mL
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aliquots were placed into 40 mL centrifuge tubes. Two aliquots were only centrifuged (C-O) and four
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were flocculated. One set of flocculation samples underwent one round of flocculation/centrifugation (F-
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1) and the other two (F-2). Twenty ng of bifenthrin, lambda-cyhalothrin, and cypermethrin were added to
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each treatment and tubes were tumbled at 20 rpm for approximately 16 h.
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The day of SPME analysis, calibration standards were prepared in deionized (MilliQ) water. 0.9 mL of
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10% by weight alum and 3 drops of 1 M NaOH were added to F-1 and F-2. C-O, F-1, F-2 were
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centrifuged at 3280 rpm for 30 minutes. C-O and F-1 were then removed for analysis while F-2
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underwent a second round of flocculation and centrifugation. 30 mL of supernatant was carefully
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transferred into a 30 mL sample vial. SPME analysis was performed as described in the Methods Section.
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Figure S8: Comparison of SPME pre-treatment methods. Error bars represent the range of duplicates.