PREDICTING PCB UPTAKE IN FISH
AFTER IN-SITU SEDIMENT REMEDIATION
Upal Ghosh Department of Chemical, Biochemical, & Environmental
Engineering
University of Maryland Baltimore County, Baltimore, MD
USEPA National Association of Remedial Project Managers conference Engineers Forum
Atlanta, GA
NRC STUDY ON EFFECTIVENESS OF DREDGING
PCB concentrations in water samples collected approximately 0.5 miles downstream of the dredging operations in the Grasse River. Dredging began approximately June 8, 2005 and ended October 21, 2005. Source: Connolly et al. 2006.
Of the 20 megasites evaluated by the NRC committee: (National Research • 25% achieved goals Council June 2007) • 50% did not achieve goals or were not monitored well • 25% not enough time has elapsed to form judgment
The report urges EPA to step up its monitoring activities before, during,
and after dredging efforts at all sediment megasites
MANAGING EXPOSURE FROM HISTORIC DEPOSITS
OF CONTAMINATED SEDIMENTS
• How do you clean up an ecologically sensitive site without destroying it?
• Contaminated sediment sites are large
• Current technologies are disruptive and expensive
• Need for innovative techniques that reduce risks
PCB contaminated wetland in VA 3
activ
ated c
arbon
soot
carbo
n
partic
ulate
coal
partic
ulate
charc
oal
heav
y fue
l oil
coal
tar
Pula
kerog
en
co lla
gen
humi
c acid
degra
ded a
lgae
amorp
hous
orga
nic m
a tter
oxidi
zed h
umic
acid
cutic
lealg
aelig
nin
ce llu
lose
seve
ral so
ils an
d sed
imen
t
NATURE OF SOIL/SEDIMENT PARTICLES
charcoal
• Sediment contains sand, silt, clays, charcoal, wood,coal char, coal, & shells
char • PCBs/PAHs bound to carbonaceous particles less bioavailable 7
wood 6
5sand 4
3shell 2
1
0
Phenanthrene partitioning for various organic materials
log
(K oc
)
Petrography images
From: Ghosh et al. Environ. Sci. Technol. 2003 coal charcoal coke 4
PCB ABSORPTION EFFICIENCY IN A CLAM
From: McLeod et al. Environ. Sci. Technol. 2004
PCB ABSORPTION EFFICIENCY IN WORMS PCB spiked to sediment or PCB spiked to AC and added to sediment 93% less uptake when PCBs associated with AC
-Side view of a lab microcosm 2 days after placing a layer of AC on sediment -AC is slowly worked into the sediment through bioturbation
Sun & Ghosh, ES&T 2007
PCB
in w
orm
(ug/
g w
et w
t.)
0.3
0.2
0.1
0.0
PCB in sediment
PCB in AC
Mono Di Tri Tetra Penta Hexa Hepta Octa Nona
PCB homolog
Beckingham et al. Environ. Sci. Technol. 2011
6
90
% re
duct
ion
in p
orew
ater
80 70 60 50 40 30 20 10
SUMMARY RESULTS FROM LABORATORY STUDIES
100 100
0 0
% re
duct
ion
in b
ioup
take
90 80 70 60 50 40 30 20 10
mar
ine
poly
chae
tes -
PCBs
(8,9
)
mar
ine
clam
s -P
CBs
(16)
mar
ine
amph
ipod
s -PC
Bs)
(9
mar
ine
wor
m -
PAH
s (10
)
fres
hwat
er o
ligoc
haet
es -
PCBs
(11)
fres
hwat
er cl
am -
PCBs
)
(16
terr
estr
ial w
orm
-di
oxin
san
d fu
rans
(15)
mar
ine
sedi
men
t -PC
Bs)
(12
mar
ine
sedi
men
t -PA
Hs
)(1
3fo
ur fr
eshw
ater
sedi
men
ts -
PCBs
(11)
mar
ine
sedi
men
t -D
DT
)(1
4flo
odpl
ain
soils
-di
oxin
san
d fu
rans
(15)
7
CONCEPTUAL MODEL OF TREATMENT
STRATEGY
Drinking water
Activated carbon amended to surficial sediments reduces contaminant exposure to food chain through:
1) Reduced bioaccumulation in benthic organisms
2) Reduced flux into water column and uptake in the pelagic food web.
3) In the long-term, the carbon amended layer is covered with clean sediment.
8
RECENT FEATURE ARTICLE IN ES&T: In-situ Sorbent Amendments: A New Direction in Contaminated Sediment Management
9
USE OF AMENDMENTS FOR IN-SITU REMEDIATION OF
SUPERFUND SEDIMENT SITES
OSWER Directive 9200.2-128FS; April 2013
10
RECENT DEMONSTRATION PROJECTS San Francisco Bay, Grasse River, Trondheim Harbor, Grenlandsfjords, CA, USA, 2006 NY, USA, 2006 Norway, 2006 Norway, 2009
SLURRY INJECTION AND ROTOTILLER.
SLURRY INJECTION AND COVERED ROTOTILLER
ACTIVE CAP OF SITE CLAY AND ACTIVATED CARBON
SLURRY INJECTION WITH AND WITHOUT CLAY
MIXTURE
Bailey Creek, Canal Creek, Berry’s Creek, Abraham’s Creek, VA, USA, 2009 MD, USA, 2010 NJ, USA, 2012 MD, USA, 2014
PELLETIZED CARBON
DELIVERY (SEDIMITE)
PELLETIZED CARBON
DELIVERY (SEDIMITE)
PELLETIZED CARBON WITH DEGRADERS DELIVERY (SEDIMITE)
PELLETIZED CARBON
DELIVERY (SEDIMITE)
APPLICATION IN A RIVER (Participants: Alcoa, EPA, UMBC, Stanford University, Anchor Env., Brennan, Tetra Tech, ArcadisBB&L, QEA)
•L-shaped silt screen to minimize suspended particle transport
•Equipment mobilized on barges
•Target dose of activated carbon = 2.5% in surficial sediments
•No measurable change in water-column PCBs downstream
•Post-treatment monitoring to continue for 2-3 years 12
IN-SITU ASSESSMENTS OF WATER QUALITY
13
In-river deployment of field exposure cages with L. variegatus for baseline study using a modified ASTM draft method (Burton et al. 2005)
L. variegatus
0.0
0.5
1.0
1.5
2.0
2.5
3.0
PCB IN WORMS AND WATER VS. CARBON DOSE 1,100
PCBs
in w
orm
s (m
g/kg
tiss
ue)
Background Background Background Background
Mixed Mixed Mixed Mixed
Injected Injected Injected Injected
Layered Layered Layered Layered
1-year after AC (2007)
2-years after AC (2008)
3-years after AC (2009)
63-99% reduction from background each year
A. Bioaccumulation in laboratory exposures
Before AC (2006)
Activated carbon (% dry wt.)
PCBs
in e
quili
brat
ed w
ater
(ng/
L)
B. Aqueous equilibrium 1,000 900
800
700
600
500
400
300
200 95-100% reduction from background each year 100
0 0 2 4 6 8 10 12 14 16
Activated carbon (% dry wt.)
• Reduced uptake in field plots with increasing AC dose
• > 90% reduction for all treatment sites in 2009 for AC dose >4%
• Little incremental benefit above 5%AC
• Greater reduction in aqueous PCBs compared to worms
LABORATORY EXPOSURE EXPERIMENTS
Water flow in aquaria tanks • Treatments:
• Clean sediment (Rhode River) • PCB impacted sediment (Grasse River) • PCB impacted sediment-treated with AC
• Replicate aquaria with passive samplers in water column and sediment
• Fish species: Zebrafish • PCB-free diet • Sampling after 45 and 90 days
Sediment
Passive samplers
Components in each aquaria15
POREWATER AND OVERLYING WATER PCBS IN
GRASSE RIVER SEDIMENT AFTER 90 DAYS
4.3
233.
2
283.
9
95.0
11.3
2.4
0.0
0.1
0.4
0.4
0.2
0.1
0
50
100
150
200
250
300
Mono Di Tri Tetra Penta Hexa
Pore
wat
er P
CBs (
ng/L
)
PCB homologs
Untreated Grasse River
Treated Grasse River
0.0
41.4
82.6
50.0
8.0
1.9
0.0 5
.0
1.4
0.8
0.2
0.2
0 10 20 30 40 50
60 70 80 90
Mono Di Tri Tetra Penta Hexa
Ove
rlyi
ng w
ater
PCB
s (ng
/L)
PCB homologs
Untreated Grasse River
Treated Grasse River
• Porewater PCB concentration was reduced by two orders of magnitude
• PCBs in overlying water was also greatly reduced (24-30 fold) and was close to that seen in the clean Rhode River sediment.
• In the PCB-impacted untreated sediment tanks, porewater PCB concentrations were 37 fold higher than the overlying concentrations indicating sediment as the PCB source to the water column.
16 16
PCB RESIDUE IN ZEBRAFISH AFTER 90 DAYS
0.4
6.5
13.1
3.9
1.9
1.0
0.1 0.
9 1.2
0.5
0.4
0.3
0
3
6
9
12
15
Di Tri Tetra Penta Hexa Hepta
C lip
id (µ
g/g
)
PCB homologs
Untreated Grasse River
Treated Grasse River
The total PCB concentration in fish decreased by a factor of 8 after treatment with AC.
17
PREDICTING PCB UPTAKE IN FISH
Steady-State Approach
Clipid ≈ Klipid.Caq Klipid ≈ KOW
Kinetic Approach dMB/dt = WB (k1CW,O+IR.α.CS)-k2 MB (Arnot & Gobas 2004)
No uptake through food- PCB-free diet
k1
k2 18 18
EQUILIBRIUM & KINETIC MODEL PREDICTIONS
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E-03 1.E-02 1.E-01 1.E+00 1.E+01
Pred
icte
d C
lipid
(µg/
g)
Observed C lipid (µg/g)
Untreated-45 days
Untreated- 90 days
Treated- 45 days
Treated 90 days
Equilibrium
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E-03 1.E-02 1.E-01 1.E+00 1.E+01
Pred
icte
d C
lipid
(µg/
g)
Observed C lipid (µg/g)
Untreated-45 days
Untreated90 days
Treated- 45 days
Treated- 90 days
Kinetic Model
• Fish are not reaching equilibrium in the 90 day exposure
19
LOW-IMPACT AMENDMENT DELIVERY TO SEDIMENT
1. Agglomerates delivered from water surface 2. Sinks to sediment surface and resists resuspension 3. Breaks down slowly 4. Mixed into sediment by bioturbation 5. Binds contaminant and reduces uptake in the aquatic food chain 20
Sedi
Mite
™
RESTORATION & REMEDIATION OF MIRROR LAKE,
DOVER, DE
• Urban lake sediments impacted with PCBs and PAHs
• Ecological restoration will include removal of sand bar and creation of wetlands
• In-situ treatment of surface sediments with AC to reduce exposure.
• Monitoring includes PCBs in porewater, surface water, benthic invertebrates, and fish.
• In addition, ongoing inputs are being tracked.
Link to video documentary
KEY MESSAGES Amendment with AC will be most effective at:
• sites that are depositional in nature • sites less prone to sediment erosion • where native bioavailability of contaminants is high • ongoing contribution from off-site sources have been controlled.
AC amendment provides several advantages over traditional methods: • less disruption to benthic habitats in sensitive systems • amenability to shallow or constricted locations • potential for lower cost • less concern about mobilizing buried contaminants
In-situ amendments can also be used in combination with other remedies: • possible to incorporate AC into sediment caps • apply AC during and immediately after a dredging hot spots to minimize
aqueous contaminant release from resuspended sediments and residuals.
Ghosh research group at UMBC
ACKNOWLEDGEMENTS UMBC Graduate Students and post docs:
Xueli Sun; Barbara Beckingham; Adam Grossman; Jeff Thomas; Piuly Paul, Jennifer Jerschied, Seokjoon Kwon, Sonja Fagervold
Sponsors: National Institutes of Health, US Dept of Defense, SERDP/ESTCP Programs; USEPA Great lakes National Program Office; Alcoa, USEPA SBIR program; Norwegian Research Council
Current and Past Collaborators: G. Cornelissen, D. Werner; C.A. Menzie; Cindy Gillmour; R.G. Luthy; Y-M Cho, T.S. Bridges, K. Sowers, J. E. Baker
Disclosure statement: Upal Ghosh is a co-inventor of two patents related to the technology described in this paper for which he is entitled to receive royalties. One invention was issued to Stanford University (US Patent # 7,101,115 B2), and the other to the University of Maryland Baltimore County (UMBC) (U.S. Patent No. 7,824,129). In addition, UG is a partner in a startup company (Sediment
23
Solutions) that has licensed the technology from Stanford and UMBC and is transitioning the technology in the field.