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“From Flask to Field”
Treatability and Pilot Studies in Remediation
Stewart Abrams, P.E.
Omer Uppal
Presented to:
ASSOCIATION OF ENVIRONMENTAL AND ENGINEERING GEOLOGISTS
New York – Philadelphia Section December 11, 2014
Today’s Speakers
Stew Abrams, P.E.
• Director of Langan’s Remediation Technology Group
• 33 years experience in remediation and water treatment
Omer Uppal
• Senior Project Manager in Langan’s Remediation Technology Group
• 15 years experience in remediation and process engineering
Remediation Role
Site Conceptual Model
Laboratory Treatability Study
Field Pilot-Scale Study
Full-Scale Implementation
• Connects the site conceptual model with
potential remediation methods
Treatability Role
Why perform treatability?
• When there are more questions regarding
“feasibility” versus “cost-effectiveness”
• “Will it work?” versus “How will it work?”
• When a pilot test is too expensive.
Treatability Study Basics • Technologies typically “bench”
tested
• Bioremediation
• Biostimulation vs. Bioaugmentation
• Dosages of electron donor and microbial culture
• Chemical reactions (oxidation, reduction)
• Reagent dosage estimates
• Technologies not typically bench tested • Physical Processes: Air Sparging, Thermal
Pre-Treatability Indicator Tests
Chemical Oxidation • Soil Oxidant Demand (SOD)
• Theoretical amount of chemical needed to satisfy all chemical oxidant demands • Natural organic matter, reduced metals, soil matrix • Provides insight into potential dosages of oxidant.
• Can vary by oxidant
• Not expensive – possibly as low as a few $100 per sample.
Ranges of values:
• < 3 g/Kg = OK
• 3 to +/- 7 g/Kg = Probably
• 7 to 20 g/Kg = Skeptical
• > 20 g/Kg = Costly!!
volts HF 3.0 OH• 2.7 SO4• 2.6 O3 2.4 S2O8
-2 2.1 H2O2 1.8 MnO4
- 1.7 HClO 1.6 Cl2 1.4 ClO2 1.3 ClO4
- 1.4
stron
ger o
xidize
r
Fenton’s Reagent (hydroxyl radical)
Hydrocarbons – NO Cl-Ethenes – OK
Persulfate radical (activated persulfate)
Permanganate ion
Persulfate ion
Chemical Oxidation Potentials
Ozone Hydrocarbons – OK Cl-Ethanes – OK
Example – SOD Testing
SOD – Soil Oxidant Demand EAD – Experimental Alkaline Demand TAD – Theoretical Alkaline Demand
Pre-Treatability Indicator Tests
Bioremediation
• 104 cells/mL ≥ OK
• 101 to 104 cells/mL = has potential
• <101 cells/mL = ???
• Microbial Culture Counts
Do not forget other parameters:
• Nutrients
• TOC
• pH
• Sieve analysis
Et cetera . . . .
Microcosms
• Sealed bottles containing
homogenized soil and
groundwater combined with
remedial amendments
• Closed system can lead to
accumulation of inhibitory
compounds.
• Controls are critical.
• Temperature can be critical. Source: Shaw Environmental
Bioremediation Microcosm Setup
• Up to 72 bottles!
24 hours
4 weeks
8 weeks
15 weeks
25 weeks
35 weeks
Killed Control
Live Control
Biostimulation (Food Source only)
Bioaugmentation (Food Source and Microbial Culture)
Sample Time:
Column Studies
• Flow-through columns
more reflective of aquifer
conditions
• Beneficial when kinetics
are critical to cost-
effectiveness and when
permeability factors can
be significant
• Also, when commitment to
the field for a pilot test can
be problematic Source: Shaw Environmental
In Situ Microcosms
• Provide microbial,
chemical, and
geochemical information
• Shows relative
effectiveness
• No time-dependent data,
shows results only at the
end of study
“Differences in Scale”
Bench testing being performed at NJIT
Field scale pilot test Langan-owned pilot equipment
shown.
Bench scale – proof of process
Field scale – full simulation of all in situ hydrogeochemical
interactions
Treatability Study Example –
Oxidant Selection
• Permanganate
showed fast
kinetics and
better
performance.
• Performed at
Langan’s
Treatability
Facility at New
Jersey Institute
of Technology
(NJIT)
215 220 285
0.1 0.1
165
35 27
0.1
1
10
100
1000
Co
nce
ntr
ati
on
(m
g/L
)
PCE Concentration Trend
0 Day 2 Day 28 Day 7 Day 14 Day 14 Day 28 Day 7 Day
Controls Persulfate KMnO4
CVOCs: Bioremediation • Confidential client site in NJ
• Treatment of PCE with emulsified
vegetable oil (EVO)
• Biostimulation vs. Bioaugmentation
• DHC: 12.5 to 117 cells/mL
• Duration: 16 weeks
Keg of SDC-9 microbial culture
CVOCs: Chemical Reduction
• Randallstown, MD
• Treatment of PCE with zero-
valent iron (ZVI) to determine
dosage and effectiveness
• Difference in two dosages is
495,000 pounds of ZVI;
equivalent to $270,000 in
chemical costs.
• Duration: 20 days
Inorganics: Chemical Reduction
• New Jersey
• CaSx for treatment of Cr6+ in source area vadose zone soils
• Pilot test results: 96% reduction of Cr6+ in vadose zone soils
• Duration:
• Microcosms: 4 weeks (effective within 24 hours)
• Column: 17 days (effective within 5 days)
Pilot Testing
• Integrates multiple criteria:
• Geology
• Dosage
• Efficacy
• Scale-Up Economics
• The physical aspects are critical:
• Injection pressure and flowrate
• Radius of Influence (ROI)
Bioactive
Zone Bioactive
Zone
Injection Well
Piezometer Piezometer
Injection Skid
Pilot Test Network Concept
Considerations:
• Central Injection Well(s)
• Dilution water for injectant
• Target appropriate stratigraphic horizons
• Piezometers/Monitor Wells at multiple distances and depths
• Radius of Influence
• Tracer
Pilot Test Issues
• Radius of Influence
• “ROI”
• Defined as the zone
of treatment around
a remediation well.
• Need to fill pore
space around the
well.
Injection of SDC-9 for Bioremediation
Performance Monitoring Plan
• Parameters:
• Primary: VOCs, Organisms, injectant
• Secondary: TOC, ORP, Tracer, DO
• Frequency
• Expected kinetics
• Lab treatability study
• Groundwater flow velocity
Field Considerations
Presented by Omer Uppal
• Soil Vapor Extraction
• Air Sparging
• Chemical Oxidation
Soil Vapor Extraction
& Air Sparging
• Testing must occur in the field.
• Response of formation is site-specific.
• Critical parameters:
• SVE • Air Flow
• Vacuum
• Air Sparging • Air Flow
• Pressure
• Radius of Influence
Case Study I – Former Lagoon Area [FLA]
Northern NJ Site
May 2013 Air Sparge Pilot Test Remedial Technologies Tested:
• Biorespiration
• Air Sparge/Helium Tracer
• SVE/Point Permeability
FLA – Background
• Former manufacturing plant
• Primary COCs :
• Benzene up to 20,900 ug/L
• Phenol up to 12,800 ug/L
• Arsenic up to 31.2 ug/L
• Geology
• Fill layer
• Alluvium layer
• Glacial Till layer
• Hydrogeology
• Groundwater table ranges
approximately 1.5 to 6.5 feet bgs
FLA – Why Air Sparging? • Past Remediation Efforts:
• Biosparge: 2002 - 2012
• Excavation: 2012; 2,200 tons of soil
• Primary COC
• Size of Potential Treatment Area
• Source/Concentrations
FLA-Pilot Testing Activities
• Testing Methods
• SVE/Point Permeability
• Air Sparge/Helium Tracer
• Biorespiration
• Parameters of Interest
• Air flow rate
• Pressure
• Vacuum
FLA – Pilot Testing Activities
FLA – Pneumatic Modeling
Results/Considerations MDFIT – Computer Pneumatic Modeling Program
5.5 scfm
8.5 scfm
13 scfm
0
20
40
60
80
100
120
140
160
180
0 2 4 6 8 10 12 14 16
Vac
uu
m (
in H
2O
)
Distance from Test Well (feet)
Permeability Calibration for Engineered Fill Material
5 SCFM
7.5 SCFM
10 SCFM
12.5 SCFM
MeasuredVacuum
Calibrated Permeability Kr = Kz = 3.50E-08 Kc = 1.83E-06
5.4 scfm
6.75 scfm 8.9 scfm
11 scfm
0
50
100
150
200
250
300
0 5 10 15 20
Vac
uu
m (
in H
2O
)
Distance from Test Well (feet)
Permeability Calibration for Native Soils
5 SCFM
7.5 SCFM
10 SCFM
12.5 SCFM
MeasuredVacuum
Calibrated Permeability Kr = Kz = 3.70E-08 Kc = 7.79E-08
• Leaky Confining Layer
• Low Permeable Vadose Zone
• Shallow Water Table
Pneumatic Modeling
Modeling resulted in a more cost-
effective optimization strategy.
Sparging Trench Dimensions
5 to 10 ft
Where:
C L,e = COC concentration in reactor/trench effluent (ug/L), 20 ft
C L,i = COC concentration in reactor/trench influent (ug/L),
Qg = Gas or air flow rate (ft3/day),
QL = Liquid or groundwater flow rate per unit length (ft3/day),
Hc = Henry’s law constant (unitless), and Groundwater Flow
φ = Saturation parameter
Where:
K(La)COC = Mass transfer coefficient for COCs (1/day), and
V = Volume of reactor per unit length/porosity (ft3).
System Design • High Water Table
• Artificial Cap
• Horizontal SVE Wells
• Leaky Confining Layer
• Impermeable Membrane
• ROI
• 10-15 feet - 53 sparge wells
• 15 feet - 41 SVE wells
• Prevent Over Pressurization
• Pulsing Strategy
• Chimney Wells
Remedy Implementation • System Construction Ongoing
• Startup planned for March 2015
• Anticipated Cleanup Timeframe - 3 to 5 years
Case Study II - Push-Pull ISCO
North Central NJ Site
• 98 Acre Former Industrial R&D Facility
• Trichloroethene (TCE) impacts in soil and
groundwater
Extent of TCE Plume (1 ppb)
Groundwater
Flow Direction • Groundwater
concentrations of TCE
up to 59,000 ppb
(PIW-1B, Nov 2011)
• Bulk of TCE impacts
in the intermediate
bedrock zone
Phase I ISCO Pilot Test – November 2011 • Three injection wells
• 6,081 gallons of 2.5% potassium permanganate
• 1,260 lbs. of oxidant
• Three day operation
• 97% of solution injected into the Deep Bedrock
Zone (Flow rate = 5 to 22 gpm at 60 psi)
• Shallow and Intermediate Bedrock: No
measureable flow at injection pressures up to 100 psi
Phase II ISCO Pilot Test – April 2012
• Hydraulic fracturing can achieve flow rates of up
to 15 gpm at pressures less than 50 psi.
• Hydraulic influence was observed at distances
up to 125 feet during injection.
• Groundwater daylighting was observed at
PIW-1C.
Full-Scale ISCO Remedy Design Remedial Strategy:
• Installation of six additional intermediate bedrock zone injection wells, one extraction well
• Hydraulic fracturing of select injection wells
• ISCO with NaMnO4
“Push-Pull ISCO Approach”
Full-Scale ISCO Implementation – October 2014
Full-Scale Implementation….
Similar ISCO Approach Another Site
Thanks!
Questions?
Sometimes it is worth
the expense to get the
data. . . . .
Guess what this is?