case1 engineering company:obayashi corporation · obayashi corporation zengineering company :...
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Obayashi Corporation
Engineering company : Obayashi corporation one of the largest general contractor in Japan
Site Location: Nagoya, Japan
Site Area : 6,780.8m2 Treatment Area : 6,780.8m2 Depth : 12m
Hydrogeology in brief : Upper sandy and lower silty sand unit was separated by discontinuous silty-claylens. Hydraulic conductivity varied between 10-3 to 10-4 cm/sec. From initial stage the groundwater was anaerobic because of high natural TOC.
Contamination signature : Groundwater ・TCE (up to 40 times of Japanese environmental standard 0.03mg/L) ・cis-DCE(up to 190 times of Japanese environmental standard 0.04mg /L)
Soil ・TCE (up to 19 times of Japanese environmental standard 0.03mg/L) ・cis-DCE (up to 14 times of Japanese environmental standard 0.04mg /L)
Treatment : Pump and treat was done for several months. As a result the contamination concentration was reduced.
・TCE(up to 10 times of the environmental standard 0.03mg/L)
・ cis-DCE(up to 100 times of the environmental standard 0.04mg /L) )
This is followed by injection of EDC.
Case1Case1
Engineering CompanyEngineering Company::
ORP contour map showing change after injection
Prior to EDC injection Inception of EDC injection
1 week after the start of injection Completion of the injection
Case 1 Case 1 Engineering CompanyEngineering Company:: Obayashi CorporationObayashi Corporation
TCE concentration change
Post EDC injection
2.5 months after the injection2 months after the injection
Prior to EDC injection
TCEconcentration
Case 1 Case 1 Engineering CompanyEngineering Company:: Obayashi CorporationObayashi Corporation
cis-DCE concentration change
Post EDC injection
2.5 months after the injection2 months after the injection
Prior to EDC injection
cis-DCEconcentration
Case 1 Case 1 Engineering CompanyEngineering Company:: Obayashi CorporationObayashi Corporation
DAYS (up to injection of EDC)
Concentration(mg/L)
VC
Ethylene
MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
•Site location: Kanto region, Japan•Site characteristics: The site has sandy-silt and silty units with hydraulic conductivity less than 10-4cm/sec. The contaminated depth was up to 10-15 m from GL with the concentration of TCE and cis-DCE varying from less than 1 mg/L to more than few hundred mg/L in the groundwater.
•Treatment: Bioremediation was directly applied without heat treatment at the locations with contamination concentration approximately 100mg/L or below.
Engineering CompanyEngineering Company::
cis-DCE
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• At the locations with more than 100 mg/L of contamination concentration the remediation was done in two phases. the subsurface was heated at up to 80oC and soil gas and groundwater was extracted under vacuum.
•Once the concentration fell below 100mg/L EDC was injected. Groundwater from the surrounding area was used as the microbial seed while diluting EDC.
Case 2Case 2 Engineering CompanyEngineering Company:: MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
Two Phase treatment
> 100mg/ℓ ~ 10mg/ℓ >Concentration
Subsurface heating and Gas/liquid phase vaccum extraction
EDC based bioremediation
Method
Case 2Case 2 Engineering CompanyEngineering Company:: MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
DNAPL containing zone was heated followed by vaccum extraction of soil
gas and groundwater.
Results
Application of heat resulted in incresed permeability of formation. Gas extraction volume increased from 20-60L/day (before heating to 100-400L/day after heating).
Monitoring well Hearting points
Monitoring well
Filler
Sandy-silt
Hydraulic conductivity
Heating zone
Temp.(40-60℃)/
Electric heater
Silty- sand
Case 2Case 2 Engineering CompanyEngineering Company:: MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
Post EDC based bioremediation
Results of phase 1 & 2 treatments
TCE concentration
c-DCE concentration0m 5m 10m 15m
● Monitoring well
● Heating points
◆ EDC injection well
Concentration by the environmental standard
×1 ×1000×10 ×100
Case 2Case 2 Engineering CompanyEngineering Company:: MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
Initial stage Post Heat-treatment
Post Heat-treatment EDC based bioremediation
Inception of EDC based bioremediation
1 5 10
1000
Concentration (mg/L)
100
10
1
0.1
0.01
0.001
TCE (Japanese environmental standard 0.03mg/L)
cis-DCE (Japanese environmental standard 0.03mg/L)
(month)
Case 2Case 2 Engineering CompanyEngineering Company:: MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.MITSUI MINERAL DEVELOPMENT ENGINEERING CO., LTD.
KOA KAIHATSU CO., LTD
Locations Soil Gas Survey Results
Ground water contamination plumeTarget treatment Area with contaminationexceeding environmental standard
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Engineering CompanyEngineering Company::
Hydrogeological modeling for EDC injection design
Case 3Case 3 EngineeringEngineering Company: KOA KAIHATSU CO., LTDKOA KAIHATSU CO., LTD
PCE concentration change
30-Jan-2004 (Prior to injection)
03-Oct-2005
50000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
200000
250000
50m0 0.001
0.01
0.1
0.2
0.3
0.4
0.5
1
1.5
2
2.5
50000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
200000
250000
50m00.001
0.01
0.015
0.02
17-Dec-200450000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
200000
250000
0 50m0.001
0.01
0.02
0.03
0.04
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Case 3Case 3 EngineeringEngineering Company: KOA KAIHATSU CO., LTDKOA KAIHATSU CO., LTD
30-Jan-2004 (Prior to injection) 17-Dec-2004
03-Oct-2005 31-Jan-2006
50000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
200000
250000
50m0 0.01
0.04
0.08
0.12
0.16
0.2
0.24
0.28
50000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
200000
250000
50m00.004
0.04
0.05
0.06
0.07
0.08
0.09
0.1
0.12
50000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
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0 50m0.004
0.04
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0.08
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50000 100000 150000 200000 250000 300000 350000 400000
50000
100000
150000
200000
250000
0 50m0.004
0.04
0.05
0.06
cis-DCE concentration change
Case 3Case 3 EngineeringEngineering Company: KOA KAIHATSU CO., LTDKOA KAIHATSU CO., LTD