Bioremediation-From the Lab to the Field - PowerPoint PPT Presentation

About This Presentation
Title:

Bioremediation-From the Lab to the Field

Description:

Chlorinated Aliphatic Hydrocarbons - aerobic electron donor (DCM, CM, DCA) ... mixing and delivery for bioremediation of chlorinated aliphatic hydrocarbons ... – PowerPoint PPT presentation

Number of Views:109
Avg rating:3.0/5.0
Slides: 14
Provided by: mla54
Learn more at: https://clu-in.org
Category:

less

Transcript and Presenter's Notes

Title: Bioremediation-From the Lab to the Field


1
Bioremediation-From the Lab to the Field
Mitch Lasat, Ph.D. NCER/ORD
1
2
Presentation Outline
  • What is Bioremediation?
  • Why Bioremediation works?
  • Contaminants amenable to Bioremediation
  • Limiting factors (why bioremediation doesnt
    work?)
  • Engineering strategies for Bioremediation
  • Is bioremediation a hot research topic for the
    EPA?
  • Bioremediation research

2
3
What is Bioremediation?
  • the use of biota to degrade/mitigate
    environmental contamination
  • -bioremediation- by microorganisms (soil,
    groundwater-organic contaminants)
  • -phytoremediation- by plants (mostly soil and
    surface water)

3
4
Why Bioremediation works?
  • microorganisms obtain energy for growth by
    degrading organic contaminants
  • in an enzyme-mediated process- direct
    metabolism
  • -aerobic biodegradation of BTEX in the presence
    of an oxygenase (Pseudomonas)
  • some enzymes are not very specific and in
    addition to the growth substrate
  • transform other compounds-cometabolism
  • -oxygenases are not very substrate-specific and
    can also degrade TCE
  • (however TCE cannot be used as a growth
    substrate)

4
5
Contaminants amenable to Bioremediation I
  • Hydrocarbons
  • - BTEX (aerobic and anaerobic biodegradation)
  • - PAH (less amenable)
  • - aerobic degradation via cometabolism
  • - anaerobic
    biodegradation (naphtalene-denitrification)
  • Chlorinated Aliphatic Hydrocarbons
  • - aerobic electron donor (DCM, CM, DCA)
  • - anaerobic electron donor (TCE, DCE)
  • - anaerobic acceptor (PCE, TCE)-
    dehalorespiration
  • - cometabolism (aerobic, anaerobic-reductive
    dechlorination)
  • Chlorinated aromatic hydrocarbons
  • - PCB (in general bioremediation recalcitrant)
  • -aerobic, less chlorinated
  • -anaerobic (dehalorespiration)
  • - PCP aerobic, anaerobic (groundwater-reductive
    dechlorination)
  • - Dioxins highly resistant to Bioremediation

5
6
Contaminants amenable to Bioremediation II
  • Pesticides
  • -chlorinated highly resistant to aerobic
    transformation
  • -phosphorus based and carbamate quickly
    hydrolyzed
  • -triazine biodegradable
  • Explosives
  • -biotransformation is partial (TNT) or slow
    (RDX)
  • Inorganics
  • -bacterial reduction of Hg2 to Hg0
  • -bacterial reduction of Cr6 to Cr3

6
7
Factors that limit the potential for
Bioremediation (why Bioremediation doesnt work)
  • 1) Contaminant-related limitations
  • Synthetic vs. natural contaminants
  • -bioremediation potential greater for
    natural compounds
  • Physical characteristics
  • -density, Henrys constant, solubility,
    octanol/water partition coefficient
  • Molecular structure of the contaminant
  • extent of chlorination, linear vs. branched
    structure, saturated vs.
  • unsaturated compounds

7
8
Factors that limit the potential for
Bioremediation (why Bioremediation doesnt work)
  • 2) Environmental conditions
  • Hydrogeology permeability/hydraulic
    conductivity, heterogeneity,
  • fracture bed rocks, soil properties, pH
  • Nutrients CNP-100101
  • Electron acceptor oxygen (3 parts of oxygen to
    converts 1 part of
  • hydrocarbon to CO2), nitrate, sulfate, ferric
    iron
  • 3) Microorganisms presence
  • Assessment of microbial activity, introduced
    microorganisms

8
9
Engineering Strategies for Bioremediation
  • Intrinsic bioremediation/natural attenuation
  • Enhanced/engineered bioremediation
  • -addition of nutrients, oxygen
  • Bioaugmentation
  • -introduction of appropriate organisms

9
10
Phytoremediation
  • Phytoextraction (removal/extraction of toxic
    metals- Pb)
  • Phytodegradation (organics degradation in roots
    and shoots-
  • TPH, PAHs,
    BTEX, pesticides, CAHs)
  • Phytovolatilization (CAHs, Hg, Se)
  • Evapotranspiration/Hydraulic control (plume
    reduction)

10
11
Is bioremediation a hot research topic for the
EPA?
  • Cross-agency research advisory workgroup for
    Goal 3 Bioremediation- a
  • priority technology for remediation of
    contaminated sediments,
  • groundwater and soil
  • ORD GOAL 3 MYP-long-term goal oriented with
    annual progress measured
  • by completion of APG/APM-of the approximately
    70 remediation-related
  • APMs, approximately half pertain to
    bioremediation
  • - Report on biodegradation of PAHs in sediments
  • - Report on solvent-enhanced residual
    biotreatment of residual DNAPL
  • - Develop and evaluate microbial populations for
    effective TCE biodegradation
  • - Develop and evaluate cost-effective methods
    for nutrient mixing and delivery for
    bioremediation of chlorinated aliphatic
    hydrocarbons
  • - Synthesis report on 5 DNAPL remediation
    technologies

11
12
  • Bioremediation research I
  • ORDs Goal 3research program is designed to
    provide a better understanding
  • of the traditional risk management options
    (dredging, capping, pump and
  • treat), and to investigate alternative options
    (bioremediation, MNA)
  • Problem-driven research program, supporting
    research needs of
  • - Office of Solid Waste
  • - Superfund
  • - Leaking Underground Storage Tank Corrective
    Action
  • - Oil Spills
  • Contacts NPD-Randy Wentsel
  • NRMRL-Trish Erickson
  • NCER-Mitch Lasat

12
13
  • Bioremediation research II
  • NCER Bioremediation research
  • - 1997-2001 several RFAs on Bioremediation and
    Phytoremediation
  • - 2001 HSRC program was recompeted, research
    focus on contaminated
  • sediments, VOC-contaminated groundwater,
    mine wastes,
  • phytoremediation
  • http//es.epa.gov/ncer/grants/
  • Case studies/performance data
  • http//clu-in.org/techfocus/
  • - site general information
  • - contaminants
  • - site hydrology
  • - media
  • - cleanup goals
  • - technology used
  • - results/costs
  • - lessons learned

13
Write a Comment
User Comments (0)
About PowerShow.com