Overview of Site Remediation Technologies Gas inFusion Systems for Groundwater Remediation

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Overview of Site Remediation Technologies Gas
inFusion Systems for Groundwater Remediation

• Jim Begley
• inVentures Technologies Inc. (iTi)

Represented By
Offering you the finest environmental
contracting services, products remedial
technologies available
Contact Craig Marlow 8248 Hidden Forest Drive,
Holland, Ohio 43528 Phone [phone] Fax
419.867.8976Cell 419.349.7970 Email
cemarlow_at_att.net
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Presentation

• Introduction to Gas inFusion technology
• Bioremediation Alternatives
• iSOC system design
• gPRO Systems for active gas infusion and enhanced
  NAPL recovery

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iTi Gas inFusion Technology
Microporous Hollow Fiber

• Mass-transfer of gasses to groundwater w/out
  sparging

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Mass Transfer- Gas to Liquid

• Solubility
• Driving force unique to each gas
• Interfacial Surface
• Pathway for gas molecules to contact liquid
• Gas inFusion Technology Provides Large
  Interfacial Surface

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Dissolved Gas Conditions

• Saturation
• The condition of a liquid with the maximum
  possible stable quantity of a solute at a
  specific temperature and pressure
• Supersaturation
• An unstable condition of a solution with a solute
  at a concentration exceeding saturation
• Gas inFusion Technology can achieve saturated
  and supersaturated conditions

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iSOC Technology
Microporous Hollow Fiber

• iSOC in situ Submerged Oxygen
  Curtaininnovative gas delivery technology

iSOC provides large interfacial surface area as a
pathway for gas molecules to contact and dissolve
in groundwater
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Typical iSOC Well Schematic
Valve Box
Regulator and Manifold
Tubing
Gas inFusion Well
Gas Supply
Water Table
inFusion Well Screen (High Flow Screen)
typically 0.010 to 0.030 slot width
Grout Seal
Sand/Gravel Pack
Contaminated Groundwater Treatment Zone
Filter
Lifting Line
Groundwater Flow
Well Sump ( 1 ft below iSOC)
iSOC Unit
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iSOC System
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HiSOC Hydrogen Gas Hose Connection
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gPRO HP Active Dissolved Gas Substrate Delivery
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gPRO HP w/ Oxygen Generator
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Mobile gPRO HP Setup
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gPRO Gas inFusion System
Water Supply
Gas Supply
Injection Pump
gPRO HP Modules (multiple modules in series and
parallel)
Injection Wells
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Remedial Applications

• Passive and Active in situ bioremediation
• Oxygen for aerobic treatment
• Oxygen and cometabolic substrates (alkane and
  alkene gases) for lower chlorinated compounds,
  1,4-dioxane, NDMA
• Hydrogen for reductive dechlorination of
  chlorinated solvents, denitrification and
  perchlorate reduction
• Abiotic Geochemical Fixation of metals (H2 and
  O2)
• pH adjustment with CO2
• NAPL recovery enhancement with CO2 Saturated
  Water Injection (SWI)

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Bioremediation Microbes at Work

• Conceptual

• The Real Thing

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Direct Aerobic Groundwater Bioremediation

• Soil microorganisms are stimulated to degrade
  contaminants of concern
• Oxygen is the preferred electron acceptor
• Contaminant is the food
• Products are biomass, carbon dioxide and water

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Direct Aerobic Treatment
Hydrocarbons solvents e.g. VC
Eating
Breathing
Gas
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Aerobic Treatment of Petroleum in Groundwater

• Process requires a balanced source of
  macronutrients carbonnitrogenphosphate
  (C100N10P2)
• Hydrocarbon is the carbon source for energy and
  growth of biomass
• Every gram of BTEX requires 3.14 grams oxygen for
  complete degradation

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Anaerobic Reductive Dechlorination

• Anaerobic dehalorespiring bacteria
  (Dehalococcoides ethenogenes) use H2 as electraon
  donor (food) and chlorinated solvents (e.g. PCE)
  as an electron acceptor (breathing PCE)
• 20 grams of PCE can be degraded with 1 gram of
  H2

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PCE
Most Oxidized
TCE
DCE
VC
Ethene
Most Reduced
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Anaerobic Reductive Dechlorination
Eating
Breathing
PCE, TCE
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Aerobic Cometabolic Oxidation of Lower
Chlorinated Solvents (TCE, DCE, VC)

• Bacteria use a continuous supply of oxygen as the
  electron acceptor
• A cometabolic substrate (e.g. alkane gas) is
  supplied as a growth substrate (electron donor)

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Aerobic Cometabolic Oxidation

• Cometabolic substrate induces the production of
  enzymes that catalyze the oxidation of TCE, DCE
  and VC (lower CAHs)
• Bacteria gain energy from the cometabolic
  substrate, not from the chlorinated solvent

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Aerobic Cometabolic Treatment
Eating
Breathing
From EPA July 2000
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Example DesigniSOC Plume Biobarrier System
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iSOC Treatment Zone
MW-X
GW-Flow
MW-Y
Concentration
MW-X
MW-Y
Distance
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iSOC Area of Influence and Treatment Zone
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Key Design Information

• Site hydrogeologic data
• Contaminant concentration and distribution
• Groundwater geochemistry and nutrients
• Biological parameters
• Remedial objectives
• Access limitations

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Site Groundwater Flow
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Extent of Groundwater Contamination
Receptor Stream
Source Area
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Problem Statement

• Wells containing dissolved petroleum constituents
  exceeding their respective RBSLs (MW-1, MW-4,
  MW-8, MW-11, MW-15, MW-17, and MW-19)
• Surface water samples from Salt Creek
  downgradient indicated the presence of MTBE (main
  concern)

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Evaluation of Oxygen DemandArea and Hydrogeology
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Evaluation of Oxygen DemandAqueous and Sorbed
CoCs
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Evaluation of Oxygen DemandAqueous and Sorbed
CoCs
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Gas Supply and Delivery Rate
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Treatment Layout

• Orientation and spacing based on groundwater flow
  and oxygen demand
• 15 to 20 ft crossgradient spacing in two fences
• 4 treatment well line downgradient to protect
  receptor stream
• 5 treatment wells to address oxygen demand in the
  target area
• Anticipated period of operation to address oxygen
  demand (3 years)
• Longer term operation required to maintain cut
  off without source remediation

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iSOC Well Layout
Treatment Shed
Proposed iSOC Treatment Wells
70 feet
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What about the source area?

• High hydrocarbon concentrations indicated the
  presence of possible residual hydrocarbon
  saturation or trapped LNAPL
• Alternative technologies were more appropriate
  for the source area in the given time frame for
  remediation

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Example Case StudygPRO HP Oxygen Gas inFusion
and Subsurface Delivery
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Field Trial Plan

• Field trials were designed to evaluate
• Feasibility of high concentration oxygenated
  water injection
• Oxygen distribution in the subsurface (reported
  here) and
• Affects of oxygen delivery on contaminants of
  concern

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gPRO Oxygen System

• inVentures Technologies gPRO HP system with
  oxygen generator

System Constructed by Cornelsen Limited
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Injection Trial System

• gPRO 4-module system oxygenating municipal water
  supply
• 3 injection wells in a cluster
• Injection depth approx 3.5 meters below land
  surface
• Sheet pile isolation of test lane
• Groundwater flow parallel to lane

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Field Trial Test Lane
Injection Wells
Monitoring Wells
Lane C
Groundwater Flow
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gPRO Operation and Monitoring Data
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Initial Oxygen Distribution 2/08
gt2 mg/L
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Peak Oxygen Distribution 4/14/08
gt12 mg/L
gt18 mg/L
gt6 mg/L
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NAPL Source Zone Remediationutilizing
Supersaturated Water Injection (SWI) Gas
inFusion Technology
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Enhancement of NAPL Recovery With SWI

• Water is supersaturated with CO2 in the gPROHP
  System
• Supersaturated (carbonated) water is injected
  into the aquifer in and below the NAPL zone
• CO2 bubbles nucleate in the aquifer
• Hydrocarbons volatilize into CO2

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Enhancement of NAPL Recovery

• NAPL coats the gas bubble and is mobilized up for
  non-aqueous phase extraction
• Trapped NAPL ganglia are displaced by CO2 and
  mobilized for non-aqueous phase extraction
• Groundwater, NAPL and soil vapor are removed
  through dual phase extraction wells

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Technology Mechanisms
Spontaneous spreading of NAPL over water in the
presence of gas and the subsequent transfer of
volatile NAPL constituents into the growing gas
bubbles


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Technology Mechanisms
Upward mobilization of NAPL contacted by gas
phase carbon dioxide



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Proof of concept in the lab In situ gas
saturation development and rate of gas evolution
Bubble flow meter
Vg2
Vg3
Vg1
Water outlet and level control
Vw
Saturated porous medium
Injection
Production
Supersaturated water, C
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Gas evolution during SWI Experiment
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In situ gas evolution in the presence of
impermeable barriers
SWI
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Recovery of residual hexane by SWI
Volatile NAPL is removed by gas evolution
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Field Application
SWI well
Multiphase extraction well
Unsaturated Zone
gPRO HP
Contaminated Zone/Trapped NAPL
Induced Flow
Saturated Zone
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Design Considerationsfor Selection of iSOC and
gPRO Systems

• iSOC for enhanced natural attenuation and passive
  plume cut off biobarriers
• Lower substrate mass requirements
• Broad range of geologic conditions
• gPRO systems for active high mass substrate
  delivery
• High substrate demand or NAPL recovery
• Geologic conditions suitable for extraction and
  reinjection
• Enhance ETR systems and targeted source area/hot
  spot treatment

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Questions?
Jim Begley inVentures/MT Environmental
Restoration jbegley_at_cape.com
www.gPROinfo.com
www.isocinfo.com
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Contact
Offering you the finest environmental
contracting services, products remedial
technologies available
Craig Marlow 8248 Hidden Forest Drive, Holland,
Ohio 43528 Phone [phone] Fax [phone]
Cell 419.349.7970 Email cemarlow_at_att.net