Case1 Engineering Company：Obayashi Corporation · Obayashi Corporation zEngineering company :...

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


cis-DCE concentration change

Post EDC injection

2.5 months after the injection2 months after the injection

Prior to EDC injection

cis-DCEconcentration


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.


cis-DCE

Case2Case2

• 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


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


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


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)


KOA KAIHATSU CO., LTD

Locations Soil Gas Survey Results

Ground water contamination plumeTarget treatment Area with contaminationexceeding environmental standard

Case3Case3


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


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

200000

250000

0 50m0.004

0.04

0.06

0.08

0.1

0.12

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


Case1 Engineering Company：Obayashi Corporation · Obayashi Corporation zEngineering company :...

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