Bioremediation: The Most Efficient Method of

Reducing Oil Pollution

Biotechnology DesignAthens, Georgia

2014

Problem Oil, a key natural resource in today’s

society, is a major threat to the environment and will continue to be harmful unless ways to inhibit its side effects on the environment are developed.

For example, the Gulf of Mexico BP oil spill in June, 2010, absolutely disrupted the ocean shoreline ecosystem and devastated the many life forms along the coast because of a lack of oil eating bacteria in the sand, resulting in oil-contaminated sand.

Problem+ Oil, or gasoline, constantly leaks and is dropped

on the roads by cars. Then, when it rains, this oil is washed into rivers and other freshwater systems as runoff, eventually ending up in the soil along the shores of freshwater systems. Then, the polluted soil poisons nutrients, which are digested by plants and animals, resulting in the deaths of numerous species.

+ This disrupts the ecosystem and possibly causes some species to become endangered. This is a major issue because oil-contaminated freshwater systems are also responsible for providing fish, which are fed on by other animals.

Effects of Oil Pollution Oil spills can contaminate the land, causing devastation of

species and ecosystems. When a pollutant enters an ecosystem at a lower level in the

biomass pyramid, this pollutant is magnified by a power of ten each level up. This results in the death of many tertiary and quaternary predators, which can have a very negative effect on the ecosystem. [We can further explain the negative effects (overgrowth of the species below them, that kills off the producers at the bottom)].

(Gaps)

Effects of Pollution Death of Wildlife

Exxon Valdez Oil Spill An estimated 250,00 seabirds, 2,800 sea otters, 300 harbor seals,

250 bald eagles, 22 killer whales, and billions of salmon and herring eggs died as a result of the oil pollution produced by the spill.

Despite various methods and efforts made to remove the oil from the area, oil can still be found over 20 years after the spill.

Treatments used: hot water, high pressure cold water, mechanical cleanup, and bioremediation. The hot water method was determined to be causing more harm to the environment than the oil spill, and the fertilizer used with the bioremediation method was toxic to marine life.

Oil can block air passageways, resulting in the suffocation of animals.It can also inhibit the insulting properties of fur and feathers on animals. Oil is toxic if ingested.

(“Tarred and Feathered”)

(Smith)

(Smith)

Effects of Pollution Oil spills can also have negative effects on humans.

If oil comes into contact with a person’s skin, it can irritate the skin and/or be absorbed through it.

Many components of oil are volatile and evaporate easily. These components can be inhaled.

Humans can also suffer from oil spills through the consumption of contaminated food. “Some of the oil hydrocarbons such as PAHs bioaccumulate in fish and other organisms and may concentrate many times more than in water or other media.”

When an oil spill occurs on land, the oil may spread vertically through the soil, eventually reaching the ground water. It may also spread laterally, enlarging the area of affected soil.

(Small-scale Oil Leak)(Underground Oil Leak Spreading into a Stream) (Ungdom)

Effects of Pollution Underground oil spills, such as

from the leaking of pipelines or underground storage tanks, increase the chances of polluting the ground water as the vertical distance is shorter.

With oil spills such as the Deep Horizon spill, some of the oil may remain in the environment for over 100 years.

“Recent studies have shown that oil spills lower soil fertility and cause poor growth of plants.” (The Adverse Impacts of Oil Pollution on the Environment and Wellbeing of a Local Indigenous Community: The Experience of the Ogoni People of Nigeria) (Environmental Impact of the BP Oil Spill)

Possible Treatments

("Flowchart of Soil Remediation")

Bio-Soil Treatment

• Bioremediation• Bioventing• Landfarming• Landspreading

Bioventing A type of bioremediation where air

is blown into or pulled out of soil to supply oxygen to the bacteria. This helps the bacteria in the soil grow more efficiently and allow them to break down the contaminant, such as oil that is ultimately broken down into carbon dioxide and water.

Advantages:•Uses readily available equipment; easy to install. • Creates minimal disturbance to site operations. Can be used to address inaccessible areas (e.g., under buildings). • Requires usually 6 months to 2 years under optimal conditions (short treatment). • Is cost competitive: $45-140/ton of contaminated soil. • Easily combinable with other technologies (e.g., air sparging, groundwater extraction). • May not require costly off gas treatment.

(Bioventing Process)

Disadvantages of Bioventing• High constituent concentrations

may initially be toxic to microorganisms.

• Not applicable for certain site conditions (e.g., low soil permeabilities, high clay content, insufficient delineation of subsurface conditions).

• Cannot always achieve very low cleanup standards.

• Permits are generally required for nutrient injection wells (if used). (A few states also require permits for air injection.)

• Lastly, even though bioventing is a plausible and feasible oil cleanup method, it does not work as well with heavier contaminants, such as oil, in comparison to light contaminants, such as gasoline, that evaporate easily.

("Principle of Bioventing")

Landfarming A biocell , a liner surrounded

by a berm, is used to place the contaminated soil in , and the soil is then fertilized and turned periodically, breaking down the contaminant. Simultaneously, the berm is used to control the water running onto and off of the contaminated soil, and any water that seeps through the soil is collected by perforated pipes, a leachate collection system placed above the liner, preventing contamination spreading from the area to groundwater. Also, monitor wells are placed around the area to test whether or not any contamination has escaped.

Advantages:• Relatively simple to design

and implement. • Requires usually 6 months to

2 years under optimal conditions.

• Cost is $30-60/ton of contaminated soil.

• Effective on organic constituents with slow biodegradation rates.

("Figure 4.29.jpg") Landfarming Process

Disadvantages of Land Farming

• Difficult to achieve to concentration reductions greater than 95% and less than .1 ppm• Not effective for high constituent concentrations (> 50,000 ppm total petroleum hydrocarbons). • Presence of significant heavy metal concentrations (> 2,500 ppm) may inhibit microbial growth. • Volatile constituents tend to evaporate rather than biodegrade during treatment. • Requires a large land area for treatment. • Dust and vapor generation during landfarming aeration poses air quality concerns.

("Biofarming")

Landspreading • Landspreading consists of tilling

contaminated soil into the surface layer of a field and letting natural biological action and aeration clean up the contamination.

• The main difference between landspreading and landfarming is that landfarming is a more active method, because it involves fertilizing and re-tilling the area.

• In both cases, periodic soil samples are tested to check on how breakdown of the contaminants is progressing.

Mechanical/Engineering /Methods

• Soil Vapor Extraction• Soil Washing• Natural Attenuation and Monitoring• Incineration

Soil Vapor ExtractionSoil vapor extraction (SVE) involves placing perforated pipes in contaminated soil and vacuuming the air out of the soil. This works well if the contaminant is a volatile compound, like gasoline, which easily turns into a vapor. The air may then be treated before being released. Often, it is used on piles of contaminated soil that have been excavated, and on soil that is still in place. Advantages:•Minimal disturbance of the contaminated soil•Treatment of larger volumes of soil than possible by excavation•Product recovery•Cost efficient and cost effective compared to excavation and pump and treat systems•Clean up spills before chemicals reach the water tableDisadvantages:•Theoretical design equations are nonexistent•The design of SVE systems is basically empirical•Ineffective when the concentrations of the contaminant are low

Soil Vapor Extraction

("Soil Vapor Extraction (SVE)")

Soil WashingSoil washing involves removing contamination from soil, gravel, and rocks through dissolving the contaminant by using water or a solvent, and the contaminated soil must be moved from its original location to an area where the contaminated wash water can be collected and treated.

Advantages of Soil Washing Cost effective when reducing the amount of soil that needs further

treatment or disposal performed under ideal conditions, can lead to a volume reduction

of approximately 90% of the originally contaminated soil (Sharma and Reddy 2004)

Performed on-site so the large volume of soil that is not contaminated after washing can be reused as backfill at the site.    

Performed in a closed system where conditions, such as pH and temperature, can be controlled and closely (Sharma and Reddy 2004)

generally the process can be run at a very high rate of around 100 cubic yards per day (US EPA 1996)

Can remove a range of contaminants, both organic and inorganic, from the soil at the same time Requires a few permits in order for it to be used, making it a relatively easy method to employ.

Disadvantages of Soil Washing

• Requires a large area in order to set up the system• Will not reduce the volume of salty or clayey soils as quickly

with gravely soil• Further treatment is expensive and might not save any time or

money• Generally, ineffective for soils containing more than 30 to 50%

silt, clay or organic matter  • Wastewater needs specialized treatment, which is difficult and

expensive• Sludge remnants requiring further treatment or disposal off site• Air emissions from equipment increase the cost of the operation

and reduce its appeal• Exposure of the public to contaminants from contaminated soil

being excavated and handled ex situ.

Soil Washing

("BioGenesis Sediment Washing Process")

Natural Attenuation and Monitoring (MNA)Natural attenuation, consisting of dilution, volatilization, adsorption, and biodegradation, can be used for both soil and water. It may be allowed in lieu of cleanup if there is little chance that the contamination will pose a threat to people, plants or animals and when other treatment is impractical or impossible. When this solution is allowed, the contaminated soil or water must be monitored to show that the contaminant level has decreased and a health or environmental problem does not exist. Generally, monitoring must be carried on for a longer time in Alaska, because natural attenuation can take much longer due to cold temperatures and short daylight in the winters.

("Innovative-Technologies-1.jpg") ("MNA1.jpg")Monitoring Equipment ("Washclosure10.JPG")Oily Dirt

Advantages of MNAAs with any in situ process, generation of lesser volume of remediation wastes, reduced potential for cross-media transfer of contaminants commonly associated with ex situ treatment, and reduced risk of human exposure to contaminants, contaminated media, and other hazards, and reduced disturbances to ecological receptors;• Some natural attenuation processes may result in in-situ destruction of contaminants;• Less intrusion as few surface structures are required;• Potential for application to all or part of a given site, depending on site conditions and remediation objectives;• Use in conjunction with, or as a follow-up to, other (active) remedial measures; and• Potentially lower overall remediation costs than those associated with active remediation.

("0909-AFRACKING-oil-shale_full_600.jpg")

Rock with Oil Streaks

("Division WIG Ram Island")Shoreline

Disadvantages of MNALonger time frames may be required to achieve remediation objectives,compared to active remediation measures at a given site;• Site characterization is expected to be more complex and costly;• Toxicity and/or mobility of transformation products may exceed that of the parent compound;• Long-term performance monitoring will generally be more extensive and for a longer time;• Institutional controls may be necessary to ensure long term protectiveness;• Potential exists for continued contamination migration, and/or cross-media transfer of contaminants;• Hydrologic and geochemical conditions amenable to natural attenuation may change over time and could result in renewed mobility of previously stabilized contaminants (or naturally occurring metals), adversely impacting remedial effectiveness; and• More extensive education and outreach efforts may be required in order to gain public acceptance of MNA.

IncinerationSoil contaminated with hazardous substances that can be burned at moderately low temperatures and result in safe byproducts are good candidates for incineration. Chemicals that need a much higher temperature or do not form safe byproducts can still be incinerated, but the job must be done at a special incinerator with good air quality control devices. If a large amount of soil must be treated, a mobile incinerator can be brought to a site. In-state soil burners are able to handle oil-type spills. Soil contaminated with hazardous wastes, like PCBs or solvents, must be shipped out of state because they require special types of EPA-approved incinerators that are not available in Alaska.

However, the process undertakes only a small capacity and is very expensive.

("alttechs1.jpg")Black Smoke ("Burning Smoke Fire Wooded")("Photo2DanalsIMG_6699.jpg")Three Columns of Smoke

Groundwater Treatment

• Natural Attenuation

• Air Sparging• Pump and

Treat– Natural attenuation and bioremediation are the most commonly used treatment methods for groundwater in Alaska.

Air Sparging Air sparging involves forcing air downward into a

contaminated aquifer. Air bubbles are created, moving horizontally and vertically through the soil, which creates an underground stripper that removes contaminants by volatilization. These air bubbles then carry the contaminants to a vapor extraction system. Air sparging wells can also be used to create a barrier preventing contaminated groundwater from leaving a site.

("Figure 1")Air Sparaging Process

Advantages of Air Sparging• Readily available equipment; easy installation• Implemented with minimal disturbance to site operations• Short treatment times: usually less than 1 to 3 years under

optimal conditions• At about $20-$50/ton of saturated soil, air sparging is less

costly than aboveground treatment systems• Requires no removal, treatment, storage, or discharge

considerations for groundwater• Removal is enhanced by soil vapor extraction

("Air Sparging")Air Sparaging Equipment

Disadvantages of Air Sparging• Cannot be used for treatment of confined aquifers. • Stratified soils may cause air sparging to be ineffective. • Some interactions among complex chemical, physical, and

biological processes are not well understood. • Lack of field and laboratory data to support design

considerations. • Potential for inducing migration of constituents.• Requires detailed pilot testing and monitoring to ensure vapor

control and limit migration.

("One of the Many")Stratified Soil ("Aquifer Diagram")

Pump and Treat•This method involves pumping contaminated water out of the ground, running it through a filter or other treatment system to remove the contamination, and returning the water to the ground. It is effective for any contaminant for which there is a good filter method, such as dissolved oil. It often takes many years to successfully remove the contamination.

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Time (years) Pump & treat

Permeable reactive barrier (10yr)Natural attenuation

("Cumulative Net Present Cost")

Removal of Contaminated Soil, Water, or DebrisSometimes contaminated material may have to be removed and shipped to an off-site waste treatment and disposal facility. This can happen when the contaminant cannot be removed easily by any of the methods discussed above, or when the responsible person wants to clean up and close the site quickly. (Very Expensive)

("MichCon_cleanup_CS_51_display")Removal of Contaminated Soil

("Water Images")Removal of Contaminated Water("0614_biogas_o'brienH1*304.jpg")

Waste Treatment Facility

Bioremediation•Bioremediation is the process of degrading hydrocarbons via microorganisms. Additives, such as oxygen, may be used to augment the degradation rate. These microorganisms or bacteria occur naturally in the environment. Furthermore, they can be isolated and expanded to help remediate oil spills faster.

Bioremediation• However, today’s technology mostly consists

of physical methods involving skimmers, vacuums, and in situ burning, which tend to be expensive an labor-intensive, and chemical methods, which tend to be expensive and poisonous to marine life. The Deepwater Horizon incident in the Gulf of Mexico is a great example of the challenges we face and lack of effective technology we possess in cleaning up oil contaminated soil and water.

Bioremediation• The answer to this problem is bioremediation.

According to the Environmental Protection Agency, due to a greater efficiency, the government and industries see bioremediation as a high priority. Additionally, microbial cells can be manipulated to be able to withstand various environments including both soil and water simultaneously, which would solve oil contamination issues along the shoreline on beaches.

Advantages of Bioremediation• The process is an ecologically safe and natural

process. It is "natures way" of solving contamination problems.

• Bioremediation is cost effective. The process is generally 60-70% less costly than other technologies.

• Little disruption of surrounding, non-contaminated areas.

• Virtually no investment in "capital equipment".• Can remediate areas that are not easily accessible

or inaccessible to other technologies.

Advantages of Bioremediation• Bioremediation can be accomplished in-place

(In Situ) thereby eliminating the hazard of "off-site" contamination caused by digging, hauling and transporting of contaminants to other areas.

• Air quality and air pollution concerns from volatile chemical evaporation are eliminated.

• After bioremediation is completed, the environment is virtually restored to its pristine condition.

• The process poses no health or safety risks to your employees thereby reducing insurance costs.

Disadvantages of Bioremediation

If the process is not controlled it is possible the organic contaminants may not be broken down fully resulting in toxic by-products that could be more mobile than the initial contamination.The process is sensitive to the level of toxicity and environmental conditions in the ground i.e. the conditions must be conducive to microbial activity e.g. need to consider temperature, pH etc.Field monitoring to track the rate of biodegradation of the organic contaminants is advised.If an ex-situ process is used, controlling volatile organic compounds (VOCs) may be difficult.

("Bioremediation of a Polluted Canal Before and After")

Disadvantages of Bioremediation

Treatment time is typically longer than that of other remediation technologies. Range of contaminants that can be effectively treated is limited to compounds that are biodegradable. Leaves residual levels that can be too high (not meeting regulatory requirements), persistent, and/or toxic. Performance evaluations are difficult because there is not a defined level of a "clean" site and therefore performance criteria regulations are uncertain

("Grease Trap Treatment")

("Bioremediation")Bioremediation via Plants

("Bioremediation")

Solution Bioremediation: Transfect a common soil and water bacteria, so that oil can be degraded in

various environments.

("Bioremediation")Bioremediation via Plants

Application If the bacteria are successfully transfected, it is

possible that plants could be transfected. Organisms could be made to contain this gene, passing it on to their offspring and perpetuating the spread of the ability to naturally decompose harmful oil present in the environment. Plants containing this gene would be able to remove oil from the environment safely and efficiently. Various species could be transfected to ensure that all, or almost all, sources of water were treated. Transfecting various species of plants would also enable the process to occur in marine, freshwater, and land environments.

Application The transfected bacteria would be used to

remove the oil from the sand on the ocean floor in the event of an offshore oil spill. To prevent harming the organisms in the sand on the shore and other places, this bacterium could be inserted into the specific ecosystems. It would decompose the oil, safely removing it from the environment without harming other organisms. The bacterium itself would not negatively affect the ecosystem and would therefore be an ideal solution to this pressing problem.

Real-Life Application: Altogen Labs

+Altogen Lab, Texas-based biotechnology company, scientists have found these oil-degrading bacterial strains to be naturally present in various types of soil and water; however, upon contamination with crude oil, the concentration of bacteria increases dramatically because these bacteria feed on oil. Unfortunately, this process only occurs on the edge of the oil spill, as most microorganisms need other nutrients and oxygen to survive, making the ecosystem relatively inefficient for bioremediation.

("Order Now")("Soil Bioremediation Products and Services")

Real-Life Application: Altogen Labs Altogen Labs developed a technology that allows

the acceleration of this natural process. Scientists were able to identify a hydrocarbon-degrading bacterial population, including saturate degraders and polycyclic aromatic hydrocarbon degraders, and optimize the growing process in the laboratory. They developed a method of cultivation of oil-degrading bacteria that are specific to the site of a particular spill - microbes that act on the hydrocarbon molecules that are present at the site of the pollution.

Application The remarkable feature of this development is that

bacteria can be expanded in large aqueous volumes and then the water can be evaporated to store high concentrations of bacteria in dry form and low volume. The product is very stable, and dry, natural bacteria can be activated by the addition of water. The growth conditions of these natural bacteria were optimized for effective oil degradation in Texas soil (including variations in temperature and soil conditions, as well as a number of oil compositions).

Altogen Labs is actively working on further development of this technology for both soil and water applications. However, the current product development process is limited to laboratory scale, and industrial-grade production and commercial product launch will require additional scale-up work. The company is now looking for collaborative opportunities to enable this large-scale development project.

Application When a power plant is struck by

lightning, it is possible for small oil leaks to occur. These leaks are often difficult to detect, harm the organisms in the vicinity and can sometimes contaminate the ground water.

The transfected bacteria would remove the oil from the ground water, making it potable. The released oil also has a lethal effect on the nearby plants and animals; the addition of this transfected bacterium would prevent the death of organisms and regain the health and safety of the ecosystem.

(Tim)

Lightning over Salem Nuclear Power Plant in NJ