Ministry of Science and Technology
Taiwan, R.O.C.
2015 Southeast Asia International Joint-Research and Training Program
『To Promote Sustainable Protection and Restoration of Soil and Groundwater Environment』
Sediment Contamination:
Protection and Remediation
Shu-Chi Chang, Ph.D., P.E., P.A.
Department of Environmental Engineering
National Chung Hsing University
Outline
•
•
•
•
•
•
Introduction
Sediment contamination
Protection of sediment
Properties of typical contaminants
Sediment remediation
Conclusion
Introduction
•
•
•
•
•
What is sediment
A dynamic system
Is it originally pristine
A status quo in Taiwan
Why do we care about sediment?
1
What is sediment
• Sediments are fragmented materials that
originate from weathering and erosion of
rocks or unconsolidated deposits and are
transported by, suspended in, or deposited by
water.
(USEPA, 2014)
• 底泥：指因重力而沉積於地面水體底層之
物質。
• Sediment: those substances, due to gravity,
deposited at the bottom of a surface water
body. (TWEPA)
1-1
A dynamic system
•
•
•
•
•
•
•
•
•
Erosion of the surface materials within a water shed
Transport of suspended particles
Deposition of suspended particles
High flow velocity event can re-suspend the deposited
particles and re-deposit
During low flow rate period, some may be blown into
air
Water chemistry plays a big role at tidal reach
sections
How about some contaminants in small quantities
How about some contaminants in large quantities
Microbes and benthic organisms
1-2
Is it originally pristine
• Very hard to judge
• Initially eroded particle may be pristine
• Litters and organic matter may be present at
the middle and downstream section
• Human activities may cause higher BOD and
exceed the self purification capacity
• Farming and industrial activities may
introduce persistent organic compounds
1-3
A status quo in Taiwan
• Full survey is underway
• Selectively monitored heavily polluted rivers
for specific contaminants for more than 10
years
1-4
Why do we care?
• An important link in food chain
• Estuary areas and continental shelve are
traditionally important fishing areas
• Heavy metals can enter organismal body and
accumulate (El-Moselhy et al., 2014)
• Hydrophobic organic compounds may also
accumulated and biomagnified through food
chain
• Comparatively, the cycle time could quite
short
1-5
Protection of sediment
• Administrative approach
– Guidelines for sediment quality
– Implement the guidelines
– Review the results and revise the guidelines
• Canadian could be the pioneer
– Protocol for the Derivation of Canadian Sediment Quality Guidelines for the
Protection of Aquatic Life. (CCME, 1995)
• EU regulation seemed to be delayed. No single guideline or law dedicated
sediment management yet.
• US
– EPA’s Contaminated Sediment Management Strategy (Farris et al., 1995)
• Taiwan
– Included into the “Act for soil and groundwater remediation” in 2010
– Specific guideline issued in 2012
– In 2013, a specific regulation requires the government authority in charge of
the relevant end-enterprise to finish a first-run sediment survey within 5 years
2-1
Protection of sediment
• Canadian approach as a model
– The Sediment Quality Guidelines
– How the guidelines work
• The No Effect Level: the level of the chemicals in the
sediment do not affect fish or the sediment-dwelling
organisms..
• The Lowest Effect Level: a level of contamination which
has no effect on the majority of the sediment-dwelling
organisms.
• The Severe Effect Level: At this level, the sediment is
considered heavily polluted and likely to affect the
health of sediment-dwelling organisms.
2-2
Protection of sediment
• Guideline development
– Sediment Background Approach
– Equilibrium Partitioning Approaches
– Apparent Effects Threshold Approach (AET)
– The Screening Level Concentration Approach (SLC)
– Spiked Bioassay Approach
2-3
3-1
Sediment contamination
(Mulligan et al., 2010)
Sediment contamination
3-2
•
•
•
•
Primary minerals
Secondary minerals
Organic matters
Oxides and hydrous
oxides
• Carbonates and
sulfates
(Mulligan et al., 2010)
Sediment contamination
3-3
Sediment contamination
• Contaminants
– Heavy metals
– Organic pollutants
•
•
•
•
•
•
•
•
•
•
Grease and oils
PAHs
PCBs
PBDEs
BPA
Phthalates
Chlorobenzenes
Dioxin and furans
Herbicides and pesticides
etc.
– Emerging contaminants
NAPL= non-aqueous phase liquid
3-4
Sediment contamination
• Fate and transport
(Mulligan et al., 2010)
3-5
Sediment contamination
3-6
Sediment contamination
• Bio-attenuation and bioavailability
3-7
Properties of typical contaminants
•
•
•
•
•
•
•
•
•
•
Molecular weight
Density
Water solubility
Kow
Koc
KH
Vapor pressure
Viscosity
Biodegradability
others
3-8
Sediment sampling
• Sediment sampling method（NIEA S104.31B）
– Sediment: usually consists of clay, silt, sand, organic matters,
and other mineral mixtures. After long term physical, chemical,
and through biological reaction and aquatic transport process,
then deposited on the bottom of water bodies.
– Surface sediment: the sediment 0 to 15 cm below the surface
– Deep sediment : the sediment more than 15 cm below the
surface 。
– Sampling devices: trowel or scoop, grab sampler, or core
sampler
– Considering sampling objectives, sediment, contaminants, and
the environments
– Samples
• Grab sampling
• Composite samples
– This method describes the apparatus, materials, sampling,
sample preservation, safety, and quality controls.
3-9
Samplers
3-10
Gravity corer）
Ekman dredge
Trowel
Sampling kit
Van Veen dredge
3-10
Other samplers
Smith McIntyre sampler
Open core sampler
(Mulligan et al., 2010)
Sampling points selection
Random
According to the random
number table to locate
different points
Grid sampling
Fixed distance
Zone sampling
Separate
into
several
different
homogeneous
areas and allocate sample
numbers according the
weight of area size.
Multistage
sampling
Initially large area and then
focused
on
heavily
contaminated areas
3-11
Others
• Weather
– Temp, wind, tide, wave, storm?
• Transportation
– Mass transport, rental cars, rental boats, rafts, or wading
• Special needs
– Climbing
– Taking boats
– Diving?
• Safety
–
–
–
–
Insurance
safety rope
Life jackets
Physical training
3-12
QA/QC
• Blank samples
– Field blank sample
– Trip blank sample
– Equipment blank sample
3-13
26
3-13
Blanks
• Field blank sample
– Meaning：if contaminated during sampling
process
– Prep：
Similar
matrix in
bottles
Bring to the
field
Simulate the
sampling
process
Seal and
bring back
to the lab
– Amount：every batch. One of twenty samples
and
if
not
enough
at
least
one
balnk.
Air：filter paper
groundwater：reagent water or dilution water
sediment ：soils
 Without the target pollutant(s).
3-14
Blanks
• Trip blank sample
– Meaning：To judge if the samples were
contaminated
– Prep
Similar matrix in
container
Sealed and
to the field
Sealed and back to
the lab
– Amount：every batch and at least one per 20
samples
Blanks
• Equipment blank sample
– Meaning：also called rinse blanks. To judge if
samplers are contaminated
– Prep：Collect the reagent water or solvent at the
very last step of rinsing
– Amount：every batch and at least one per 20
samples
3-15
Method selection
•
•
•
•
•
Analytes characteristics
Feasibility
Convenience
Accuracy and precision
Sensitivity
3-16
Methods and instruments
• Instruments
– Gas chromatography
• Suitable for chemicals that are thermally stable (will not
decompose or change chemical structure). The boiling point
should be lower than 350°C.
– Liquid chromatography
• Suitable for semi-volatile and non-volatile compounds and
those thermally decomposable analytes but the analytes
have to be dissolved in solvents.
• Higher molecular weight
– Ionic chromatography
– Inductively coupled plasma optical emission
spectrometry (ICP-OES)
– Atomic absorption spectroscopy
3-16
OA/QC for detection
•
•
•
•
•
Surrogate Standard
Method blank sample
Quality check sample
Duplicate sample
Spiked sample
3-17
Pretreatment
• All samples have to be determined for their water
contents
• Digestion
• Extraction
3-18
Extraction
Using accelerated
Using vacuum
to
solvent
extraction
to
Concentrate
the sample
recover
a 40-ml
sample
to a specific
with
solvent
GC-or LC
濃縮
圖5 Speed Extractor
淨化
圖6 真空減壓濃縮機
volume
（Speed Extractor E-916, BÜCHI Labortechnik AG, Switzerland）
濃縮
Using GC for analysis
3 steps：
Column:
depends定樣品
萃取
Vacuum
concentrate
to a acid
1. Concentrate
Injection:
1 µL sulfuric
specific
volume.
2. Copper
powder
Carrier
gas: Nitrogen
3. Acidic silica gel column
3-19
Heavy metal analysis (I)
• Atomic absorption spectrometry (AA)
3-20
Burner
Head
Ignitor
Assembly
3-21
Burner Mixing Chamber
AUX
Oxidant Line
FUEL
Nebulizer
Capillary
Tube
Drain Tube
NEB
Oxidant Line
Heavy metals (II)
• inductively coupled plasma- optical emission
spectrometry
• Can quantify more than 60 different metals
• No need to change lamps
• Higher sensitivity
3-22
ICP-OES
3-23
Heavy metals
3-24
Biological analysis
• Total cell
• fluorescent in situ hybridization (FISH)
• polymerase chain reaction – denaturant gradient gel
electrophoresis (PCR-DGGE)
• Real-time PCR
3.25
Remediation
•
•
•
•
Remedial technologies
Engineering practice
An example
Current research
4-1
Remedial technologies
• Physical: separation, rinsing, floatation,
ultrasonic
• Chemical/thermal treatment：oxidation,
electrokinetic, solidification, plasma
vitrification, thermal desorption
• Biological：Slurry reactor, land farming,
compositing, bioleaching,
biotransformation, phytoremediation
4-2
Engineering practices
4-3
(Adriaens et al., 2006)
Dredging
(Palermo et al, 2008)
4-4
Treatment of dredged materials
(Mulligan et al., 2010)
4-5
Confined disposal
(Netzband, 2002)
4-6
Contained aquatic disposal
(Thomas and Concord, 2005)
4-7
Capping
(Aldrich, 2010)
4-8
Active capping
•
•
•
•
•
Organic clay
Activated carbon
Ash
Apatite
reactive mat
4-9
Monitored natural recovery (MNR)
(Mulligan et al., 2010)
4-10
MNR
(Mulligan et al., 2010)
4-11
4-13
Management
Suspended solids
(Mulligan et al., 2010)
A pilot study on remediation
4-13
• Er-Ren River as an example
–
–
–
–
PAHs
PCBs
Dioxins
Heavy metals
52
Initial conditions
• PAHs
PAHs
環數
Naphthalene
4-14
二層 永寧 匯流 匯流
南萣
南萣 平均濃度 平均濃度
行橋
橋
處
下游 (上游) (下游)
2
ND
ND
ND
0.11
0.39
Acenaphthylene
3
0.06
0.32
0.35
0.11
Aceaphthene
3
1.66
2.73
2.25
Fluorene
3
0.21
1.13
Phenanthrene
3
0.23
Anthracene
3
Fluoranthene
/上限
/下限
ND
0.15
1.19
0.18
0.23
0.49
5.19
0.66
1.40
1.29
6.17
41.64
4.41
0.07
0.25
0.16
4.00
25.98
0.80
1.90
0.42
0.15
0.16
0.55
4.07
0.04
0.58
1.98
0.33
0.12
0.66
0.77
7.73
4
0.44
1.13
9.92
1.75
0.60
0.27
0.82
8.11
Pyrene
4
0.11
0.53
6.28
1.39
1.42
0.20
0.69
5.71
Benzo(a)anthracene
4
0.40
2.18
2.67
0.86
0.19
0.65
0.96
8.27
Chrysene
4
0.70
0.68 13.49 0.96
0.36
2.26
1.78
16.18
Benzo(b)fluoranthene
5
0.78 12.89 11.26 0.63
2.46
0.67
1.58
14.94
Benzo(k)fluoranthene
5
0.35
0.96
0.36
4.10
35.83
Benzo(a)pyrene
5
0.56 16.38 8.46
1.18
0.96
0.80
3.52
29.50
Indeno(1,2,3-cd)pyrene
6
0.19
5.86
2.92
0.22
0.77
0.32
1.39
10.71
Dibenzo(a,h)anthracene
6
0.31
7.70
4.03
0.39
0.61
0.36
8.58
55.79
Benzo(g,h,i)perylene
6
0.27
6.73 13.07 1.85
1.06
0.49
3.06
26.08
5.66 26.34 0.73
4-15
Heavy metal and PCBs
analytical results, mg/kg
value/reg.
value/
upper
limit
value/
lower
limit
NA
NA
NA
NA
0.111
45.50%
272%
22%
271%
9.33
1.4
15.00%
16%
28%
85%
1.15
1.16
0.021
1.80%
6%
46%
178%
360
354
355
4.16
1.20%
142%
152%
467%
648
641
640
643
4.36
0.70%
161%
410%
1286%
Hg
0.378
0.274
0.304
0.319
0.054
16.80%
2%
37%
139%
Ni
167
166
164
166
1.53
0.90%
83%
208%
692%
Pb
194
193
196
194
1.53
0.80%
10%
120%
404%
Zn
818
796
830
815
17.2
2.10%
41%
212%
582%
Contaminants
1
2
3
Mean
Stdev
CV
Nap
<0.01
<0.01
<0.01
NA
NA
PCBs＊
0.369
0.155
0.209
0.244
As
7.72
9.97
10.3
Cd
1.18
1.14
Cr
352
Cu
PCBs degradation pathway (1)
(Borja et al., 2005）
4-16
PCBs degradation pathway (2)
(Borja et al., 2005）
4-17
Nanoemulsion in lab test
組別
• Lab result
– PCBs
– As and Cr
NC
NE1
NE2
NE3
NLC
NLE1
NLE2
NLE3
NHC
NHE1
NHE2
NHE3
TC
TE1
TE2
TE3
TLC
TLE1
TLE2
TLE3
THC
THE1
THE2
THE3
4-18
厭氧
k(day-1)
R2
-0.0129
-0.0083
-0.0089
-0.0094
-0.0217
-0.0166
-0.0086
-0.0109
-0.0125
-0.0110
-0.0080
-0.0163
-0.0069
-0.0104
-0.0020
-0.0040
-0.0079
-0.0063
-0.0019
0.0014
-0.0075
0.0030
0.0009
-0.0025
0.3020
0.6022
0.5009
0.7803
0.7983
0.8869
0.3953
0.9407
0.5581
0.7064
0.7902
0.7975
0.3256
0.6774
0.1512
0.4612
0.8901
0.6287
0.7942
0.2053
0.4457
0.0618
0.3027
0.5007
好氧
kave. (d-1)
-0.0099
-0.0144
-0.0119
-0.0058
-0.0037
-0.0015
k(day-1)
R2
-0.0166
-0.0121
-0.0063
-0.0010
-0.0148
-0.0183
-0.0106
-0.0014
-0.0128
-0.0067
-0.0052
-0.0052
-0.0080
-0.0047
-0.0136
-0.0009
-0.0118
-0.0055
-0.0068
-0.0037
-0.0152
-0.0040
-0.0083
-0.0042
0.3948
0.4639
0.1643
0.1588
0.5210
0.7818
0.6016
0.0191
0.5470
0.2503
0.1061
0.6934
0.1358
0.1514
0.6769
0.0053
0.5510
0.0939
0.1329
0.1148
0.4245
0.0719
0.2874
0.0551
kave. (d-1)
-0.0090
-0.0113
-0.0075
-0.0068
-0.0069
-0.0079
As Removal
4-19
As removal
4-20
Nanoemulsion
• 成分：大豆油、食品級界面活性劑、水
4-21
4-22
Experiments
Group
NR
Adsorptin
Biostimulation
Integrated
No.
MNP
MNP recovery
SONE
1
0 mg/L
N
0
2
0 mg/L
N
0
3
0 mg/L
Y
0
4
20 mg/L
Y
0
5
Y
0
6
1000 mg/L
0 mg/L
N
0.10%
7
0 mg/L
N
1.00%
8
0 mg/L
N
10.0%
9
Y
0.10%
10
20 mg/L
1000 mg/L
Y
0.10%
11
20 mg/L
Y
1.00%
12
1000 mg/L
Y
1.00%
4-23
Process（1）
790
5
470
G
H
K
D
62
J
I
110
C
B
200
E
95
90
F
210
10
480
100
100
A
Process（2）
63
4-24
33
32
10/26/11
10/23/11
10/20/11
10/17/11
10/14/11
10/11/11
10/8/11
10/5/11
10/2/11
9/29/11
9/26/11
9/23/11
9/20/11
9/17/11
9/14/11
9/11/11
9/8/11
9/5/11
9/2/11
8/30/11
8/27/11
8/24/11
8/21/11
8/18/11
8/15/11
8/12/11
8/9/11
8/6/11
8/3/11
7/31/11
7/28/11
7/25/11
7/22/11
7/19/11
7/16/11
7/13/11
7/10/11
7/7/11
7/4/11
7/1/11
6/28/11
6/25/11
6/22/11
6/19/11
6/16/11
6/3
SONE注入，
32
開始循環
6/13/11
33
6/10/11
6/12/11
6/14/11
6/16/11
6/18/11
6/20/11
6/22/11
6/24/11
6/26/11
6/28/11
6/30/11
7/2/11
7/4/11
7/6/11
7/8/11
7/10/11
7/12/11
7/14/11
7/16/11
7/18/11
7/20/11
7/22/11
7/24/11
7/26/11
7/28/11
7/30/11
8/1/11
8/3/11
8/5/11
8/7/11
8/9/11
8/11/11
8/13/11
8/15/11
8/17/11
8/19/11
8/21/11
8/23/11
8/25/11
8/27/11
8/29/11
8/31/11
9/2/11
9/4/11
9/6/11
9/8/11
9/10/11
9/12/11
9/14/11
9/16/11
9/18/11
9/20/11
9/22/11
9/24/11
9/26/11
9/28/11
9/30/11
10/2/11
10/4/11
10/6/11
10/8/11
10/10/11
10/12/11
10/14/11
10/16/11
10/18/11
10/20/11
10/22/11
10/24/11
10/26/11
6/10/11
6/7/11
6/4/11
6/2/11
5/30/11
Field measurement
4-25
• 底泥上方與底泥中Temp
6/10
MNP注入，
暫停循環一天
31
溫度_1
30
溫度_2
溫度_3
29
溫度_4
溫度_5
28
溫度_6
27
溫度_7
溫度_8
26
溫度_9
溫度_10
25
溫度_11
溫度_12
24
6/10
MNP注入，
暫停循環一天
31
溫度_1
30
溫度_2
溫度_3
29
溫度_4
溫度_5
28
溫度_6
27
溫度_7
溫度_8
26
溫度_9
溫度_10
25
溫度_11
溫度_12
24
7.8
6/10/11
6/12/11
6/14/11
6/16/11
6/18/11
6/20/11
6/22/11
6/24/11
6/26/11
6/28/11
6/30/11
7/2/11
7/4/11
7/6/11
7/8/11
7/10/11
7/12/11
7/14/11
7/16/11
7/18/11
7/20/11
7/22/11
7/24/11
7/26/11
7/28/11
7/30/11
8/1/11
8/3/11
8/5/11
8/7/11
8/9/11
8/11/11
8/13/11
8/15/11
8/17/11
8/19/11
8/21/11
8/23/11
8/25/11
8/27/11
8/29/11
8/31/11
9/2/11
9/4/11
9/6/11
9/8/11
9/10/11
9/12/11
9/14/11
9/16/11
9/18/11
9/20/11
9/22/11
9/24/11
9/26/11
9/28/11
9/30/11
10/2/11
10/4/11
10/6/11
10/8/11
10/10/11
10/12/11
10/14/11
10/16/11
10/18/11
10/20/11
10/22/11
10/24/11
10/26/11
5/30/11
6/1/11
6/3/11
6/4/11
6/6/11
6/8/11
6/10/11
6/12/11
6/14/11
6/16/11
6/18/11
6/20/11
6/22/11
6/24/11
6/26/11
6/28/11
6/30/11
7/2/11
7/4/11
7/6/11
7/8/11
7/10/11
7/12/11
7/14/11
7/16/11
7/18/11
7/20/11
7/22/11
7/24/11
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7/28/11
7/30/11
8/1/11
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8/7/11
8/9/11
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8/25/11
8/27/11
8/29/11
8/31/11
9/2/11
9/4/11
9/6/11
9/8/11
9/10/11
9/12/11
9/14/11
9/16/11
9/18/11
9/20/11
9/22/11
9/24/11
9/26/11
9/28/11
9/30/11
10/2/11
10/4/11
10/6/11
10/8/11
10/10/11
10/12/11
10/14/11
10/16/11
10/18/11
10/20/11
10/22/11
10/24/11
10/26/11
Field measurement
8
7.8
7.6
7.4
7.2
7
8
6/10
MNP注入，
暫停循環一天
7.6
7.4
7.2
7
6.8
4-26
• 底泥上方與底泥中pH
8.4
6/10
6/3
SONE注入， MNP注入，
暫停循環一天
8.2 開始循環
pH_1
pH_2
pH_3
pH_4
pH_5
pH_6
pH_7
pH_8
pH_9
pH_10
pH_11
pH_12
6.8
8.4
8.2
pH_1
pH_2
pH_3
pH_4
pH_5
pH_6
pH_7
pH_8
pH_9
pH_10
pH_11
pH_12
6
5
4
3
6/10/11
6/12/11
6/14/11
6/16/11
6/18/11
6/20/11
6/22/11
6/24/11
6/26/11
6/28/11
6/30/11
7/2/11
7/4/11
7/6/11
7/8/11
7/10/11
7/12/11
7/14/11
7/16/11
7/18/11
7/20/11
7/22/11
7/24/11
7/26/11
7/28/11
7/30/11
8/1/11
8/3/11
8/5/11
8/7/11
8/9/11
8/11/11
8/13/11
8/15/11
8/17/11
8/19/11
8/21/11
8/23/11
8/25/11
8/27/11
8/29/11
8/31/11
9/2/11
9/4/11
9/6/11
9/8/11
9/10/11
9/12/11
9/14/11
9/16/11
9/18/11
9/20/11
9/22/11
9/24/11
9/26/11
9/28/11
9/30/11
10/2/11
10/4/11
10/6/11
10/8/11
10/10/11
10/12/11
10/14/11
10/16/11
10/18/11
10/20/11
10/22/11
10/24/11
10/26/11
7
5/30/11
6/1/11
6/3/11
6/4/11
6/6/11
6/8/11
6/10/11
6/12/11
6/14/11
6/16/11
6/18/11
6/20/11
6/22/11
6/24/11
6/26/11
6/28/11
6/30/11
7/2/11
7/4/11
7/6/11
7/8/11
7/10/11
7/12/11
7/14/11
7/16/11
7/18/11
7/20/11
7/22/11
7/24/11
7/26/11
7/28/11
7/30/11
8/1/11
8/3/11
8/5/11
8/7/11
8/9/11
8/11/11
8/13/11
8/15/11
8/17/11
8/19/11
8/21/11
8/23/11
8/25/11
8/27/11
8/29/11
8/31/11
9/2/11
9/4/11
9/6/11
9/8/11
9/10/11
9/12/11
9/14/11
9/16/11
9/18/11
9/20/11
9/22/11
9/24/11
9/26/11
9/28/11
9/30/11
10/2/11
10/4/11
10/6/11
10/8/11
10/10/11
10/12/11
10/14/11
10/16/11
10/18/11
10/20/11
10/22/11
10/24/11
10/26/11
Field measurement
6/10
MNP注入，
暫停循環一天
6/10
MNP注入，
暫停循環一天
4-27
• 底泥上方與底泥中DO
8
10/ 1
DO meter故障，
暫停量測20天
6/3
SONE注入，
開始循環
DO_1
DO_2
DO_3
DO_4
4
DO_5
DO_6
3
DO_7
DO_8
2
DO_9
DO_10
DO_11
1
DO_12
0
6
5
DO_1
DO_2
10/01
DO meter故障，
暫停量測20天
DO_3
2
1
0
DO_4
DO_5
DO_6
DO_7
DO_8
DO_9
DO_10
DO_11
DO_12
Field measurement
4-28
• ORP
500
400
300
6/10
MNP注入，
暫停循環一天
6/3
SONE注入，
200 開始循環
ORP_1
ORP_2
ORP_3
100
ORP_4
ORP_5
0
ORP_6
ORP_7
-100
ORP_8
ORP_9
-200
ORP_10
ORP_11
-300
ORP_12
-400
-500
500
400
300
ORP_1
ORP_2
200
ORP_3
1006/10
MNP注入，
暫停循環一天
0
ORP_4
ORP_5
ORP_6
ORP_7
ORP_8
-100
ORP_9
ORP_10
-200
ORP_11
ORP_12
-300
-400
6
6
6
6
6
6
6
6
6
6
6
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
1
1
1
1
1
1
1
1
1
1
1
1
1
-500
4-29
Nap removal
NR
NR
adsorption
Biostimulation
Integrated
4-30
Removal
PCBs removal
NR
NR
adsorption
Biostimulation
Integrated
Evaluation
NR
Adsorption
Biostimulation
4-31
Integrated
Case conclusion
4-33
• Could be used for removal of PCBs, naphthalene, and heavy
metals。
• Adding small amount of nanoemulsion can enhance the removal
of PCBs and adding small amount of magnetite nanoparticles can
further improve the effects.
• Under aerobic conditions, it is not recommended to use
nanoemulsion.
Research focus
•
•
•
•
•
In situ
No disturbance
fast
No derived negative impact
Low cost
5-1
Outlook
• Risk assessment
• Uncertainty
• Highly cost-effective technologies need to be
studied
5-2
Conclusion
• Sediment is very important environmental
matrix that should be protected
• The regulation is still under developing for
most countries
• Methods for sampling and analysis are ready
• Risk assessment for local conditions and
better remedial technology are in demand
5-3
Acknowledgement
• Financial support from Ministry of Sciences
and Technology of R.O.C. through a grant of
NSC 98-2622-E-005-024-CC2
• Financial support from Environmental
Protection Administration of R.O.C. through a
grant of EPA-99-GA103-03-A236-17
5-4