“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?