On-site Remediation of Sea Sediment and Soil Contaminated with Crude Oil at Tae-An In the first year of research, key achievements included developing a sketch for an integrated system to treat contaminated soil using thermal desorption and soil washing processes. Parametric studies identified optimal conditions, such as a thermal desorption temperature of 400°C and surfactant concentration 15 times the critical micelle concentration for soil washing. The second year will focus on completing a pilot-scale system and testing it using real contaminated sediments and soils from the Tae-An oil spill site.

1. “On-site Remediation of Sea Sediment and
Soil Contaminated with Crude Oil at Tae-An”
M.M.Binte, Kyunghoon Choi, and Woojin Lee
The 2nd HRHRP Research Outcome Presentations
(HIGH RISK HIGH RETURN PROJECT)
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HSCERL Hazardous Substances Control & Environmental Remediation Laboratory
Department of Civil and Environmental Engineering
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May 20, 2009

2. Contents
Introduction1
Problem statement2
Proposal statement3
Achievement in 1st year4
5 Conclusion
6 Future plan

3. Introduction
❖ The Hebei Spirit oil spill occurred at the Yellow
Sea Coast of Tae-An County, Dec 7, 2007.
▪ Amount of oil leaked 10,800 tons.
▪ The affected region 35,000 ha.
(source: Al Jazeera English Channel.)
❖ Coastal area and sediments are contaminated by
NAPL (Non-aqueous Phase Liquid)
▪ Harmful for ecosystem and all livings there.
❖ Two years research has been proposed to
remediate the area.

4. Introduction
● The Hebei Spirit oil spill occurred at
the Yellow Sea Coast of Tae-An
County, Dec 7, 2007.
➢Carried 260,000 tons crude oil.
➢Leaked 10,800 tons.
➢Recovered approximately 4,153 tons.
(source: Al Jazeera English Channel.)
* * Therefore, still coastal area and sediments
are contaminated by NAPLs (Non-aqueous
Phase Liquids).

5. Introduction Cont’d
● The affected region (35,000 ha):
➢One of Asia's largest wetland areas.
➢Used by migratory birds.
➢Contains a national maritime park and 445 sea farms.
● NAPLs can
➢Pollute the ecosystem.
➢Give fatal and harmful effect to all livings there.
** Hence, remediation processes are needed to restore the damaged area.

6. Problem Statement
▪ Removal of oil spill relied only on oil absorbents and
other cleanup devices.
▪ There is high probability that the soil is not completely
remediated underneath the surface.
▪ In order to remediate the contaminated soil, an
integrated module type equipment which can treat
massive amount of contaminated soil has been
proposed.
** Separation of oil from soil by soil washing and thermal desorption.

7. Proposal Statement
❖ 1st year proposal
▪ Development of optimal soil washing and
thermal desorption process
• By considering various environmental factors
▪ Basic research on modified soil bed
• To enhance efficiency for off-gas treatment
▪ Sketch for the unified equipment
• Screening part
• Soil washing and thermal desorption part (main equipment)
• Off-gas treatment part

8. Proposal Statement Cont’d
❖ 2nd year proposal
▪ Complete pilot scale system
• Unifying three units
▪ Suggestion for other commercial uses
• By accomplishing restoration treatment
using real polluted soil in Tae-An.
!
❖ Possibility for additional requirement
▪ 6 months of additional research period
▪ More funding

9. 1st
Year Activities
Investigation of contaminated site
Literature review for thermal desorption and soil washing processes
Sketch for overall system
Parametric research
by optimizing significant factors
Overall system design
Achievement in 1st year-1

10. Revised Sketch Design - Screening Part
2mm sieve
63 µm sieve
Sieve shaker
Achievement in 1st year-2

11. Revised Sketch Design - Main Part
Impeller system to mix the system
Wheel to rotate the reactor 360 degree
Tray to collect the treated soil
Off-gas treatment system
Vessel for soil washing/thermal
desorption
Achievement in 1st year-3

12. Different Views of Main Part
Top view
Front view Right side view
Achievement in 1st year-4

13. Thermal Desorption
Achievement in 1st year-5
Contamination of
sand
by spiking diesel
Thermal
desorption
at 400ºC,200ºC
and 100ºC
Extraction of
remaining diesel
from sand by
ultrasonicator
Concentration of
extracted diesel
by rotary
evaporator
Analysis by GC/
FID

14. Thermal Desorption - Graph
Effect of temperature on thermal desorption of diesel
Time (min)
0 10 20 30 40 50 60
Conc.(mg/L)
0
1000
2000
3000
4000
5000
No temperature treatment (sand+oil)
thermal desorption at 400 deg C
thermal desorption at 200 deg C
thermal desorption at 100 deg C
Figure: Thermal desorption of diesel at three different temperatures.
Achievement in 1st year-6
44% removal

15. Thermal Desorption - Data Analysis
Achievement in 1st year-7
❖ For the same treatment time, thermal desorption at higher temperature
could remove larger amount of diesel from sand than that at lower
temperature.
Rate constant for different temperatures
Temperature
100¡É 200¡É 400¡É
Rateconstant(min-1)
0.0
0.2
0.4
0.6
0.8
1.0
0.0723
0.1969
0.8526

16. Soil Washing
Achievement in 1st year-8
Contamination of
sand by spiking
diesel
Soil washing
using water and
different
surfactant
concentrations
Extraction of
remaining diesel
from sand by
ultrasonicator
Concentration of
extracted diesel
by rotary
evaporator
Analysis by GC/
FID

17. Soil Washing - Graph
Achievement in 1st year-9
❖ For the same treatment time, soil washing at higher concentration could
remove larger amount of diesel from sand than that at lower concentration.
Effect of surfactant dose on soil washing
Time (hr)
0 1 2 3 4 5 6
Dieselconc.(mg/L)
0
1000
2000
3000
4000
Control (water + diesel)
CMC ¡¿ 5 times
CMC ¡¿ 15 times
55% removal
93% removal

18. Salinity Effect on Soil Washing
Achievement in 1st year-10
❖ An increasing concentration of NaCl increased the removal efficiency of diesel
from sand at constant surfactant dose .
Effect of salinity on soil washing
Conc. of NaCl
0% 1% 3% 5%
Removalefficiency(%)
80
85
90
95
100
89%
91%
96%
98%

19. Summary for Achievement
Sketch for overall system
Optimal thermal desorption condition
Parametric study for soil washing
1st Year
Achievement in 1st year-11

20. Conclusion
❖ Thermal desorption process
▪ Optimal temperature : 400ºC.
!
❖ Soil washing process
▪ Optimal surfactant dose : CMC*15 times.
▪ Salinity effect : Presence of electrolyte in sand due to sea
water can improve the removal efficiency of crude oil.
Both of the processes can be performed in our proposed equipment

21. Future Plan
Overall system Verification experiment Suggestions
Making pilot
scale system
Using crude oil
contaminated
sea sand
Other
commercial
uses

22. Thank You !