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Bioremediation of a Hazardous Pollutant

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Burning leaded gasoline. Old paint (Lead) Common Pollutants ... Can be in-situ. Inject nutrients organisms need to degrade pollutant into contaminated area ... – PowerPoint PPT presentation

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Title: Bioremediation of a Hazardous Pollutant


1
Bioremediation of a Hazardous Pollutant
  • Kevin Drees
  • IOFT 1101
  • October 15-18, 2007

2
What are hazardous pollutants?
  • Misplaced chemicals that cause a harmful effect
    in the environment
  • Types of harmful effects
  • Toxic (poisonous)
  • Carcinogenic
  • Mutagenic
  • Teratogenic (birth defects)
  • Flammable
  • Corrosive
  • Explosive
  • Endocrine Disruptive

3
Common Pollutants
  • Petrochemicals
  • Hydrocarbons (only carbon and hydrogen)
  • Mostly alkanes
  • Oil spills
  • Leaky underground storage tanks
  • Coal tar

CH3 (CH2)n CH3
4
Common Pollutants
  • PCE (perchloroethylene),
  • TCE (trichloroethylene)
  • Common drycleaning chemical
  • Most common groundwater pollutant
  • Used to clean circuit boards and degrease engine
    parts
  • Common pollutant at electronics factories,
    airports, and military facilities

5
Common Pollutants
  • Heavy metals
  • Mercury, Lead, Cadmium, Chromium, Zinc
  • Mine tailings
  • Burning coal (Mercury)
  • Burning leaded gasoline
  • Old paint (Lead)

6
Common Pollutants
  • Polychlorinated Biphenyls (PCBs)
  • Transformer fluid
  • Capacitor manufacture
  • Pulp bleaching
  • Bioaccumulates!

7
Where is the pollution?
  • Groundwater aquifers
  • Soil
  • Surface waters and sediment
  • Air

8
How do we clean up pollution?
  • Remediation
  • Ex-situ (off-site) strategies
  • Excavation/pumping, followed by
  • Landfill
  • Incineration
  • Chemical removal
  • In-situ (on-site) strategies
  • Immobilization (chemicals, wells, membranes)

9
Problems with traditional remediation
  • Expensive!!!
  • Invasive
  • Residual contamination
  • Landfilling not a permanent solution, just a
    delay tactic

10
Bioremediation
  • Bacteria eat or immobilize many types of
    pollutants
  • Bioremediation using bacteria to degrade or
    immobilize pollutants
  • Can be in-situ
  • Inject nutrients organisms need to degrade
    pollutant into contaminated area
  • Can be ex-situ
  • Excavate soil, pump water into bioreactor
  • Can use indigenous microbes, or introduce them

11
Advantages of Bioremediation
  • Cheap
  • Less invasive
  • Long-term
  • Can handle residual contamination

12
How do bacteria degrade pollutants?
  • All organisms need several things to live
  • Chemical building blocks (containing C, N, P, O,
    S)
  • Energy to power cell biochemical reactions
  • Breaking chemical bonds in food
  • Method of recycling energy-producing molecules
  • Ex respiration (oxygen)
  • Vitamins and minerals
  • Active sites of enzymes
  • Pollutants can serve as one or many of these
    requirements!

13
Ex Petroleum Degradation
  • Petroleum provides carbon building blocks for
    cells.
  • In addition, cells require
  • Nitrogen, phosphorous, and other nutrients
  • Oxygen

CH3 (CH2)n CH3
14
Todays Lab
  • Create oil-contaminated microcosms
  • Sand, water, and oil in a Petri dish
  • Introduce petroleum-degrading bacterium
  • Achromobacter sp. ATCC 21910
  • Isolated from a crude oil-contaminated beach
  • Introduce nutrients the bacteria need to degrade
    the oil
  • Fertilizer (NH4NO3, K2HPO4)
  • Carefully observe your microcosms, now and next
    week.
  • Smell, appearance

15
Experimental Setup
Dish Sand (30 gm) Oil (10 drops) Water Fertilizer (1 ml) Bacteria (1 ml)
1 X X 8 ml X X
2 X X 9 ml X
3 X X 9 ml X
4 X X 10 ml
16
Procedure
  • Label top and bottom of Petri dish with treatment
    number, lab group number, lab time.
  • Weigh out 30 g sand into each dish
  • Clean up any spilled sand!
  • Add fertilizer, bacteria, oil at stations.
  • Add water using graduated cylinder
  • Stir sand well with glass rod.
  • Clean glass rod with ethanol and a tissue between
    dishes!
  • Make observations
  • Leave completed microcosms on your bench. Your
    TA will put them in the 30C incubator

17
Safety Issues
  • Oil is toxic. Avoid contact.
  • Achromobacter sp. ATCC 21910 is related to a
    pathogen.
  • Wear labcoats, gloves, safety glasses.
  • Avoid spilling/dripping bacterial culture
  • Alert TA in the event of a spill, on the bench or
    your lab coat
  • Wipe benches down, BEFORE AND AFTER, with
    disinfectant solution.
  • Wash your hands!

18
Questions?
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