Bioremediation on Deep Horizon Oil SpillPresentation Transcript
Bioremediation of Deepwater horizon oil spill
Deepwater Horizon oil spill Oil spill on the gulf of Mexico on April 20 2010 It is the largest marine oil spill in the history 780 000 000L of crude oil were release to the sea The oil spill last for 3 months
How did it happen? Explosion happen when drilling unit tries to drill a new well A pressure apparently surged and could not be controlled Methane gas from the well under high pressure shoot all the way up and out of the drill column, expanded on the platform, and then ignited and explode
Impact on animals Oil is either: Dispersed into top layer of the ocean (aquatic wildlife directly subjected to oil toxicity and die off) Remains on the surface of the ocean On to coastal areas (oil clumps together to form tar balls which can be washed up onto coastal areas and affect the wildlife)
Oil can affect an organism via: Exposure (direct contact with the skin) Especially birds and mammals Rely on their outer coats for the ability to float and provide warmth. Drowning, hypothermia and smothering.
Oil can affect an organism via: Ingestion and/or inhalation Once Ingested or inhaled hydrocarbon, the hydrocarbon travels into the bloodstreams via respiratory tracts Mammals and birds: causing irritation and drowsiness Smaller organisms like plankton and larvae: abnormal reproduction and development
Sea turtles Gulf of Mexico is home to 5 species of sea turtles, 4 has been listed endangered Oil spill occur during turtles nesting season Oil affect mature female hatching success rate Hatchlings potentially face direct oil exposure Over 6000 sea turtles have been affected !!!
Dolphins Swimming in oiled water Inhale toxic chemicals from oil when going to the surface for air. Eye and skin lesions from continuous exposure to oil Decreased body mass due to restricted diet Over 390 dolphins are affected !!!
Birds Slick makes the water look calm which cause birds to dive into oil Coated with oil thus unable the bird to regulate their temperature Cause hyperthermia and eventually death. Over than 82000 birds are affected !!!
Environmental fate of oil in gulf Common to find oil in oil rich environment like gulf, thus hydrocarbon can be taken care of by many natural, physical and biological process
Cleaned up via natural means Oil dispersion and evaporation BP oil spill higher % of lighter hydrocarbon 24% total oil spilled evaporated Photolysis Hydrocarbon water soluble compounds (Toxic!) Biodegradation
Native microbes are use to environment containing hydrocarbon and use it as energy source
More oil content = more microbes community = higher rate of biodegradation
Settling 25% oil spilled settled in sea floor UV Ray
Cleaned up via human effort
Cleaned up via human effort Booms Separate surface oil and collect them Booms
Cleaned up via human effort Skimmer
Use of vacuum to draw out top layer of oil
Cleaned up via human effort Sorbent Absorb oil onto their surface Made of plastic or clay
Cleaned up via human effort In-situ burning Ignite oil Very efficient Hydrocarbon burn and converted to toxic compounds which are carcinogenic Water pollution turns into air pollution
Cleaned up via human effort Chemical Dispersants
Break down hydrocarbon into smaller droplets thus enhance biodegradation
Chemical itself can be more toxic than oil
Cleaned up via human effort Methods mentioned above are aggressive clean up effort which lead to more environmental problems Case study: Amoco Cadiz (oil tanker)
Released tones of heavy crude oil into coast line
Spill site too large to be treated
Only economical area treated with detergents
Untreated coastal areas fully recovered within 5 years
Treated areas are not fully recovered even after 30 years
What is Bioremediation? It is the use of microorganism to degrade chemical pollutants (especially hydrocarbon) Least environmental impact Highest efficiency Many forms of bioremediation using different microorganism
Bioremediation 1: using indigenous microbial population Oil eating microbes are native microbes found in the gulf Adapted well to environment with hydrocarbon as they utilize it for energy source Scientist first chosen oil eating microbes for bioremediation in gulf spill But many challenges faced
Challenges of using indigenous microbial population Strained time frame Oil eating microbes are useful but speed of degradation is not as effective Attempt 1: genetically modified microbes
To enhance the ability of microbes to break down hydrocarbon.
But no man made microbes are more effective than natural ones
Because hydrocarbon is complex = need complex communities of microbes to break them down
Thus man made microbes cannot compete with the complex communities which adapted well to environment
Attempt 2: chemical dispersants
Toxic to wildlife
Challenges of using indigenous microbial population Oxygen depletion
Oil spill = increase hydrocarbon = increase population of oil eating microbes = more oxygen needed = depletion of oxygen = creating more dead zones
Many creature did not die due to oil but because lack of oxygen and nutrients
Problems: 1. Thus create more environmental ill effect 2. Further slowing rate of recovery 3. To mix sufficient oxygen into gulf, magnitude of scale of a hurricane is needed
Challenges of using indigenous microbial population Nutrients High microbes population = not enough nutrients in sea to feed bacteria growth Add nutrients will only magnified problems
Challenges of using indigenous microbial population Temperature of the sea
Near surface of the water = warmer water = optimum temperature = highest metabolism rate in microbes = high rate of biodegradation
However deeper down the sea = decrease in temperature = decrease in metabolism = slow biodegradation
Problem: 1. Oil sunk 800-1400m deep
Challenges of using indigenous microbial population Anaerobic condition in deep ocean sea floor
25% of oil spilled are heavy sediments that sink to the sea floor forming tarry carpet which are harder to degrade
Deep down into the sea = no oxygen therefore only anaerobes strive
Problem: 1. Whatever is consumed by the aerobes in 10 days = done by anaerobes in 1 years
Successful Bioremediation in Gulf spill
Using arch microbes A less toxic dispersal agent A strain of naturally-occurring oxygen producing microbes that break down oil without using toxins Consume oil without damaging the environment. Not genetically engineered and help add more oxygen to water, thus help to repair dead zone and sustain ocean life
Using arch microbes Shown to have 99.97% effectiveness during a clean up effort in Louisiana It works underwater thus able to restore dead zone link to deep sea oil plumes More effective compared to other microbial product available
Using PRP The world standard for oil-spill clean up Consists of microscopic, hollow balls of beeswax which contain nutrients (nitrogen, phosphorous, potassium)
PRP® is a non-toxic, 100% all natural product
Made of beeswax
PRP® is oleophilic (attracts oil)
Is 18% hydrocarbon so absorbs oil and rejects water
Can absorb up to 20 times its own weight
When hydrocarbon is in contact with PRP, the encapsulating wax breaks down forming a hydrocarbon and wax matrix.
Simultaneously, indigenous microbes feed off of the nutrients and breakdown the hydrocarbons.
PRP® is hydrophobic (floats)
Water soluble detergents used to treat spill are high in nutrients and disperse rapidly into water column result in no control
Causing rapid growth of indigenous population which depletes oxygen in the sea
Even though PRP contains nutrients, but it stay floated. Thus reduce potential for algae blooms
PRP® maximizes hydrocarbon degradation
Nutrients in the PRP encourage the microbes to eat and flourish till oil is gone
The matrix will float on the surface of the water creating an ideal condition for biodegradation to take place as it allow PRP to obtain moisture and gain oxygen from ambient air
The only biological product that contains and remediates hydrocarbons in a microenvironment on water's surface
PRP® is effective in sensitive areas where labor intensive techniques are unproductive
PRP repels water and stay floated. Thus able to maintain its position on water surface
Enhancing the opportunity for product to come in contact with floating hydrocarbon
It also allows product to impenetrable areas where fugitive hydrocarbons are present.
Using PRP PRP® can be allowed to degrade in-situ or may be recovered for land remediation, land filling or recycling
PRP that does not have contact with hydrocarbons is inert and will eventually degrade and slowly release the nutrients
Naturally occurring microbes will survive a short time on the nutrients and wax encapsulating material
With the absence of a food source, the microbes will not survive long.
Unlike other booms which soak up oil and have to be dump
These bio booms degrade the oil and it disappears with the wax. Thus, no disposal is needed.
PRP® minimizes impacts to the environment
From the factor mentioned above, PRP produce the least environmental impact
Future Bioremediation for Gulf oil spill cleanup
Using cotton Cotton waste fibres not only able to absorb and hold oil, but they also have microbes that consume oil from the marine environment and bioremediate the oil into stable waste
Able to soak forty times their weight of oil and up to eighty times with chemical modifications
Using cotton Biodegradable
Cotton fibres are biodegradable; they have the ability to degrade naturally without causing any harm to environment
The cotton used can be cleaned and then reused for soaking up more oil
However, the absorption of cotton decreases with increasing numbers of use
Using fungi Specialize in breaking indigestible substances down into smaller particles Secrete acids and enzymes that aid in the decomposition of complex organic contaminants (breaking apart hydrocarbons). For example, when diesel oil-contaminated soil is inoculated with strains of oyster mycelia, the soil loses its toxicity in just 8 weeks.
Using fungi The mushrooms are free of petroleum products after digesting them The oyster mushrooms not only broke down oil, but also allowed other life forms to thrive thus able to restore habitat Cheap and sustainable
Oyster mushroom in seawater:
Grow in saltwater, at a rate of 75 percent, which is still extremely good considering the fast growth rate of oyster mushrooms.
The mushrooms could float cheaply on hemp “mycobooms”
The entire mycoboom is also entirely biodegradable so there is no extra cleanup involved
There are no worries in finding sufficient oyster mushrooms to provide the mycelia since it is native to the Gulf Coast and is nontoxic
The native strains of oyster mushrooms can be amplified to be used specifically in areas of the Gulf that are being affected by the oil spill
The mushrooms, as they mature, set the stage for bacteria. As the straw biodegrades, it also produces CO2, allowing bacterial growth on the mycelia and mushrooms, further degrading the hydrocarbons
Conclusion The Deepwater Horizon oil spill is the largest accidental marine oil spill in the history. It has employed Bioremediation as part of its cleanup efforts which has shown to be effective and has several benefits. Benefits include lower cost and reducing environmental impacts, creating a better, cleaner environment. Bioremediation has starting to gain recognition and are more known to the public. There has been more research and the development of Bioremediation. It is important to create a sustainable future in this area since it is proven to have much more advantages as compared to other methods.
Conclusion Although Bioremediation is able to deal with intractable environmental problems, there are still certain challenges faced in application of it. It is important for us to learn and understand how the microorganisms interact with different environments. With increasing understanding, only will the efficiency and applicability of Bioremediation grow.