1) Electrokinetically-enhanced bioremediation (EK-BIO) is being used to distribute lactate amendments and dechlorinating biomass throughout a treatment area contaminated with PCE DNAPL in low-permeability clay till. 2) After 1.5 years of operation, complete dechlorination of PCE to ethene has been observed across the treatment area as confirmed by both groundwater and soil core samples. 3) Lactate distribution and increasing levels of dechlorinating bacteria (vcrA genes) throughout the treatment area have enabled effective bioremediation of the PCE DNAPL.

1. FULL-SCALE EK-BIO OF A PCE DNAPL
IN CLAY TILL
- RESULTS AFTER YEAR 1½
mbb@niras.dk Martin Bymose, NIRAS Uppsala, Oct 15 2014

2. EK-BIO TEAM
– NIRAS A/S
• Martin Bymose
• Charlotte Riis
• Dorte Pade
– Geosyntec Consultants, US
• Evan Cox
• James Wang
– US Army Engineer R&D Center
• David Gent
– The Capital Region
• Mads Terkelsen
– Contractor
• Arkil A/S Miljøteknik
• Jes-Tec
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014 2

3. ELECTROKINETICALLY-ENHANCED
BIOREMEDIATION (EK-BIO)
3
• The challenge of low permeability materials is that most
contaminants migrate/diffuse into the low K soils
• Distribution of bioremediation amendments is poor and non-uniform
in low K materials
• Non-uniform distribution will prolong remediation and
increase costs
• EK-BIO is an approach to meet the challenge of distributing
reactants in low-permeable materials
• EK transport is independent on Kh
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

4. ELECTROKINETIC TRANSPORT
4
 An electrical field (DC) is induced in the subsurface
 Primary EK-BIO transport mechanisms in clay and silt:
• Electro migration (EM) – migration of charged ions – transport
of donor
• Elektro osmosis (EO) – bulk movement of water – transport of
biomass
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

5. 5
THE SITE
Treatment area: Hot Spot
IV
PCE DNAPL
10.000-100.000 μg CVOC/L
1.000-10.000 μg CVOC/L
100-1.000 μg CVOC/L
AREA A
AREA B
Natural flow
direction
MARTIN BYMOSE, NIRAS
Area 150 m2, depth 8 m
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

6. PROJECT SCHEDULE
• Two treatment areas: alternating active-passive phase of 90 days/ area
• Duration estimated at 3-5 years
6
Cycle 1:2012-2014 Cycle 2:2014-2015 Cycle 3:2016-2017
Stage
2
Stage
9
Stage
3
Stage
1
Stage
4
Stage
7
Stage
6
Stage
8
Stage
10
Stage
11
Stage
12
Stage
5
Status today
Injection of biomass in
area A
Injection of biomass in area B
MARTIN BYMOSE, NIRAS
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

7. ELECTRICAL FIELD
AREA A – STAGE 1 + 3
7
Anodes (+)
Cathodes (-)
Injection
wells
Monitoring
wells
Electromigra-tion:
Donor
transport
Elektro-
Osmosis:
Biomass
transport
Stage 1: Operation period dec. 2012 – apr. 2013 Stage 3: Operation period sep. 2013 – dec. 2013
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

8. ELECTRICAL FIELD
AREA B – STAGE 2 + 4
8
Anodes (+)
Cathodes (-)
Injection
wells
Monitoring
wells
Electromigra-tion:
Donor
transport
Elektro-
Osmosis:
Biomass
transport
Stage 2: Operation period juni. 2013 – aug. 2013 Stage 4: Operation period jan. 2014 – apr. 2014
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

9. FULL-SCALE EK-BIO - PHOTOS
9
Lactate tanks
Lactic acid
Katode
NaOH
Injektionsboring
Anode
Cathode
Injection well
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

10. PERFORMANCE MONITORING
10
Ground water
Each stage: 4 monitoring events
• Week 2, 4, and 8:
Field measurements, NVOC
• Week 12: Field measurements, NVOC,
VFA, CVOC, methane, ethene, ethane,
vcrA, chloride and redoxparameters
Soil cores
After each cycle
Documentation of effect in clay till
Electrode wells
Injection wells
Monitoring wells
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

11. DISTRIBUTION OF DONOR (AS NVOC)
- High donor conc in treated areas
- Partial depletion during passive stages in cycle 1
STAGE 2 STAGE 4
A
B
A
B
A
B
11
BASELINE
STAGE 1 STAGE 3
MARTIN BYMOSE, NIRAS
A
B
A
B
STAGE 5
A
B
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

12. CONTAMINANT COMPOSITION
- Dechlorination to VC & ethene in all wells
- PCE only present in few wells after stage 5
BASELINE
STAGE 2
STAGE 3
STAGE 1
STAGE 4
Molar fraction Molar fraction
STAGE 5
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014
MARTIN BYMOSE, NIRAS 12

13. DEGREE OF DECHLORINATION
- Increasing DOD through stages 1-5
13
BASELINE STAGE 2 STAGE 4
STAGE 1 STAGE 3
MARTIN BYMOSE, NIRAS
A
B
A
B
A
B
A
B
A
B
STAGE 5
A
B
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

14. CVOC CONCENTRATIONS
- Initial cDCE increase + ongoing dechlorination:
- PCE release by desorption and dissolution – possible PCE exhaustion
14
AREA A
AREA B
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

15. SOIL CORE SAMPLES vs GROUNDWATER
- Confirm dechlorination in clay till
B: Baseline C1: After cycle 1
C1 C1 C1
ADJACENT MONITORING WELL
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ BRUXELLES OCT 21 2014
15
- Decrease in total CVOC
- Decrease in PCE
- Production of cDCE, VC and
ethene
- Increase in vcrA in clay samples
from 103/gram to 106/gram
- Production of chloride
- Soil results support gw results
MARTIN BYMOSE, NIRAS
B B B
B B B
C1 C1 C1

16. KEY CONCLUSIONS
1½ YEAR OF EK-BIO OPERATION
16
• Lactate distribution across the treatment area
• VcrA numbers have increased in groundwater and clay across
the treatment area.
• Complete dechlorination of PCE to ethene
• PCE mass declining
• Soil data confirm that dechlorination is occurring in the clay till
• 1½ year of full-scale EK-BIO operation show that donor and
biomass are effectively distributed throughout the treatment
area enabling complete degradation of PCE DNAPL
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014

17. THANKS FOR YOUR ATTENTION
QUESTIONS?
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014
MARTIN BYMOSE, NIRAS 17

18. SITE BACKGROUND:
EK-BIO TESTING – KEY CONCLUSIONS
Start:
100 mg PCE/kg Day 100:
All PCE degraded
to ethene
2009 ERD bench-scale
• BIO works, also for
DNAPL
• 100% PCE DNAPL
degradation via ERD
possible with
Dehalococcoides (Dhc)
bioaugmentation
2010 EK-BIO lab test
• Lactate transport
rate 3.2 cm/day
• Increase in vcrA
numbers
• PCE dechlorination
to VC and ethene
2011 EK-BIO field pilot test
• Lactate transport rate
2.5-5 cm/day
• Increase in vcrA in
groundwater and clay
• PCE dechlorination to
VC and ethene
• PCE desorption and
dissolution
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014
MARTIN BYMOSE, NIRAS 18

19. REDOX CONDITIONS AND BIOMASS
REDOX CONDITIONS
• pH neutral in monitoring wells
• Strongly reducing conditions: sulfate reduction &
methanogenesis
DECHLORINATING BIOMASS (vcrA)
• Increasing and high levels of vcrA (108 -109 /L) in all wells
• A few wells have taken some time to reach high vrcA levels
EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014
MARTIN BYMOSE, NIRAS 19

20. PROCESS MONITORING
20
SCADA: (Daily)
• pH in electrode wells
• Recirculation flow
• Timer control
• Fast reactions on operation failures
Site visits: (bi-weekly)
• Visual inspection of system
• Refilling of tanks
• Current measurements
• Measurement of redox parameters
MARTIN BYMOSE, NIRAS EK-BIO FULL SCALE – RESULTS FROM YEAR 1½ UPPSALA OCT 15 2014