Post on 24-Feb-2018
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Using the passive sampler systemfor nitrate and phosphate
monitoring
- calibration, factor variation analysis
and field trialKatarina Svensson, Greg Morrison and Jesper Knutsson
Chalmers University of Technology
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
2/22
Chalmers University of Technology
Properties of the Empore anion-SR
extraction DiskProperties Empore Anion-SR disk
Average pore size 80 Average particle size 12 mSurface area 350 m2/gCapacity per disk 0!20 me"
R1
R1
R1
R1CHCH
CH
CH2
CH2
CH2
CHCHCH
CH2
CH2
CH2
N+
R1
HHH
Poly (styrene-divinylbenzene)
copolymer
Quatenary Ammonium
functional group
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Split view of the passive sampler
1. Protective mesh
2. Diffusion limiting membrane
(0.45 m CA)
3. Receiving disk (EmporeAnion SR)
4. Disk support
5. Sampler housing
6. Sampler housing
(Bjrklund, 2002)
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Diffusional path of a passive sampler
c#i
Diffusional path
Aueous !iffusion layer
csi
cs
concentration
cmi
cmoc#
$%3&
$%3&
$%3&
'(%)2&
Diffusion limiting mem"rane
Acceptor phase
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Calibration
w
s
c
BR =
The sampling rate (Rs) is substance
specific and is expressed as the
volume of cleared sample per time:
WhereBis the slope of the uptake
curve, and cwis the average
concentration of the substanceduring the calibration period.
tR
MMc
s
s
w0
=
The time averaged concentration in
the waterphase can then be
calculated:
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Calibration resultsPhosphate calibration curve
y # $%1&'() * '%(($
R2# '%,$(,
'
2''
&''
(''
''
1'''
12''
1&''
1(''
' -' 1'' 1-' 2'' 2-' $'' $-' &'' &-'
time (h)
Accum
ulationfactor(mL)
Nitrate calibration curve
y # -%.(21) + (&%&$
R2# '%(2(
'
-''
1'''
1-''
2'''
2-''
$'''
$-''
' -' 1'' 1-' 2'' 2-' $'' $-' &'' &-'
t (h)
Accum
ulationfactor(mL)
Rs = 138.5 mL day-1 Rs = 75.7 mL day
-1
Calibration
parameters
Temperature 14 C
pH 7.0
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Factor variation test
'%'
1%'
2%'
$%'
&%'
-%'
(%'
1 2 $ & - ( . ,
Trial set
Amount(m
g)
Nitrate
/hosphate
Factoral expriment design to
examine the influence of pH,
temperature and turbulence
ANOVA analysis of results
3 factors and 3 levels of variation
pH 5,7 and 9
temperature 7, 14 and 21 C
turbulence 50, 200 and 400
rpm
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Factor variation testpH influence
'%'
'%-1%'
1%-
2%'
2%-
$%'
$%-
&%'
&%-
-%'
- . ,
pH
amount0mg1
phosphatenitrate
Temperature influence
'%'
'%-
1%'
1%-
2%'
2%-
$%'
$%-
&%'
&%-
-%'
. 1& 21
tempearature 0C
amount0mg1
phosphateNitrate
tur"ulence influence
'%'
'%-
1%'
1%-
2%'
2%-$%'
$%-
&%'
&%-
-%'
-' 2'' &''
rpm
!is2amount0mg1
phosphate
nitrate
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Factor variation testTemperature is a major factor
influencing the uptake rate,
which could indicate that the
diffusion rate is controlled
mainly by the boundry layer
Phosphate is also significantlydependant on pH. See below.
Turbulence is not significant
at the variation levels chosen.
===
3
)
)!122
)
2!*
)2
1!2
)3 POHPOPOHPOH aaa pKpKpK
Influence of factors
*2'3
'3
2'3
&'3
('3
'3
1''3
Nitrate /hosphate
4ther
Tur"ulence
Temperature
pH
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Rya water treatment plant trial
'
'%2
'%&
'%(
'%
1
1%2
1%&
1%(
1*2- Aug ,*1( sept 1(*2$ sept
mg(nitrate)
'
'%'2
'%'&
'%'(
'%'
'%1
'%12
'%1&
'%1(
mg(phosphate)
nitrate
phosphate
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Water treatment plant resultsCalculation of results
'
'%-
1
1%-
2
2%-
$
$%-
&
&%-
5T/ 1 5T/ 2 5T/ $
trial
c(m
g/L)
6ampler C7 0mg89
5T/ !ata c 0mg89
Calculation of results
'
'%'-
'%1
'%1-
'%2
'%2-
5T/ 1 5T/ 2 5T/ $
trial
c(m
g/L)
6ampler C7 0mg89
5T/ !ata c 0mg89
Calibration Field
Temperature 14 C 19.6-19.0 C
pH 7.0 6.9-6.6
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Further work and development
:Redo the nitrate calibration curveFind and develop an internal or external standardPerform further field trialsPerform further factor variation analysis
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Calibration of passive samplersfor selected target metals
(Cu, Cd, Pb and Zn)
Katarina Svensson, Greg Morrison and Jesper KnutssonChalmers University of Technology
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Cali+ratio, -ata+ase
for metallic (olluta,ts. etals Cu Cd (+ , a,d $i
. Co,ce,tratio, ra,ge 1 10 a,d 50 g/l
. 4emperature ra,ge ) 11 a,d 18C
. Co,vectio, ,o,e )0 a,d *0 rpm
. p' *
. 6uffer 0!01 (%)3&
. -iffusio, em+ra,e Cellulose Acetate 0!)5m
. 7eceivi,g (ase 3 9mpore Celati,g e:tractio, disk
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Chalmers University of Technology
;lo#&troug system for Co,sta,t
Co,ce,tratio,sconstant bulk concentration setup (flowrate
>> Rs x n)
termostate controlled bulk temperature
rotating turntable for homogenous
convection
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Chalmers University of Technology
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Properties of the Empore Chelating
extraction DiskProperties of te Empore !elating disk
Sor+e,t (oly=styre,edivi,yl+e,ze,e>Average particle size 10m
p' sta+ility 0&1);u,ctio,al group Sodium salt of imi,odiacetic acid
R1
R1
R1
R1CHCH
CH
CH2
CH2
CH2
CHCHCH
CH2
CH2
CH2
Poly (styrene-divinylbenzene)
copolymer
At pH = 2, the carboxylate groups are ionized and exist
as neutral species; however, the nitrogen will have a net
positive charge and the molecule behaves as a weak anion
exchanger.
Increasing the pH > 5 ionizes the carboxylate groups and
both are negatively charged.
As the pH approaches neutral, the molecule functions as a
cation exchanger or metal cation chelator
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Conditioning and elution
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Conditioning and elution
Conditioning the chelating disk
Wet the disk with 20 mL of
reagent water under vacuum.
Wash the disk with 20 mL of
3.0M nitric acid or 3.0Mhydrochloric acid followed by two
50 mL water washes. Let the disk
go dry between each wash.
To put the disk in the ammonium
form (its most active form), wash
with 50 mL of 0.1M ammoniumacetate buffer at pH 5.3 followed
by several reagent water washes.
lution
Two elutions with 10 mL of 3.0 M nitric
aicd
Note: some metals might be difficult to elute
(e.g. Chromium)
Anal!sis
Perkin-Elmer ELAN 6000 ICP-MS
instrument and commercial calibration
standards.
Instrument is optimized to meet
manufacturer specifications
7/25/2019 Using the passive sampler system for nitrate and phosphate monitoring
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Chalmers University of Technology
Sampling rates
y # 2%1,-) + $.%'(
R2# '%,(,,
'
2''
&''
(''
''
1'''
12''
' 1'' 2'' $'' &''
time 0h
accumulationfactor0m91
Cu ($
y # $%(,&-) + '%2(1$
R2# '%,.&
'
2''
&''
(''
''
1'''
12''
' 1'' 2'' $'' &''
time (h)
accumulationfactor(mL)
C!
y # $%2..&) * &&%&($
R2# '%,$$
'
2''
&''
(''
''
1'''
12''
' 1'' 2'' $'' &''
time (h)
accumulationfactor(mL)
/"
y # 2%&) + (,%..
R2# '%,(
'
2''
&''
(''
''
1'''
12''
' 1'' 2'' $'' &''
time 0h
accumulationfactor0m91
;n (&
Rs = 59.5 mL day-1
Rs = 89 mL day-1
Rs = 78.8 mL day-1
Rs = 52.6 mL day-1
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Considerations for field use
Possible contamination of sampler during transport/handling - use a procedural blank
sampler
Sampler mounting - dependant on the sampling situation
Physical interferace from human activity if possible choose sampling spot in restricted
access areas Other physical interference (debris like branches, leafs etc)
Bio fouling bio inhibitors, internal/external standard correction
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Internal standard for chelating
disks? Preloading the disk using for example Cu
Saturating the disk vs. limited amount
Triggered release applying small amount of acid to the disk before deployment