A Permeable Reactive Barrier Remediation Technology Using Membrane-Attached Methanotrophic Biofilms

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A Permeable Reactive Barrier Remediation
Technology Using Membrane-Attached Methanotrophic
Biofilms

• Lee Clapp and Andrew Ernest
• Texas AM University - Kingsville
• Presented at HBCU/MI Kickoff Meeting
• March 10-11, 2003

HBCU/MI
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Problem Contaminated groundwater due to improper
disposal of chlorinated solvents
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Magnitude of Problem
HBCU/MI

• DOE
• 10,500 identified contaminated sites (1996)
• 25 contaminated with chlorinated solvents.
• Estimated cost of remediation - 63 billion
• Estimated time for remediation - 75 years
• NEED - Development of technologies to reduce
  chlorinated solvent remediation costs.
• (Ref EPA-542-R-96-005)

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Overall Research Goal
HBCU/MI
To develop a semi-passive permeable reactive
barrier (PRB) remediation technology that fosters
biological destruction of chlorinated organic
compounds by the controlled delivery of soluble
methane oxygen gas to membrane-attached
methanotrophic biofilms in the subsurface.
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Membrane-attached methanotrophic biofilm
HBCU/MI
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Use of In-situ hollow-fiber membranes for passive
gas transfer to subsurface
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Research objectives
HBCU/MI

• Evaluate effect of inter- and intra-well pumping
  on groundwater flow patterns well capture
  zones.
• Quantify effect of copper loading on soluble
  methane monooxygenase (sMMO) activity within
  membrane-attached biofilms.

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Groundwater modeling studies
HBCU/MI

• Phase 1 Characterize relationship between
  well-spacing, inter- and intra-well pumping rate,
  and capture zone.
• Phase 2 Characterize relationship between
  well-spacing, inter- and intra-well pumping rate,
  and DCE removal efficiency.

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Capture zone without pumping
Unpumped Well
Unpumped Well
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Capture zone with inter-well pumping
injection well
extraction well
injection well
extraction well
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Conceptualized flow field capture vs. number of
wells pumping rates
HBCU/MI
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sMMO expression studies
HBCU/MI

• Cultivate membrane-attached methanotrophic
  biofilms in simple chemostat systems.
• Characterize sMMO expression as a function of
  copper loading rate.

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Problem with copper sMMO repression
HBCU/MI
low copper
high copper
Type II
Type I
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Biofilm stratification may select for sMMO
membrane
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SEM of biofilm cross-section
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Membrane-attached biofilms
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Expected Results
HBCU/MI
sMMO
DCE degradation rate
pMMO
YJCH4 /JCU
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Deliverables
HBCU/MI

• Fundamental engineering data required to assess
  the feasibility of the semi-passive PRB
  technology.
• Technical reports and peer-reviewed articles on
  the science engineering of the technology.