What Is Bioremediation, and How Does It Work (With Examples)?
Bioremediation is a branch of biotechnology that uses living organisms, like microbes and bacteria, to remove contaminants, pollutants, and toxins from soil, water, and other environments. Bioremediation may be used to clean up contaminated groundwater or environmental problems, such as oil spills.
How Bioremediation Works
Bioremediation relies on stimulating the growth of certain microbes that utilize contaminants like oil, solvents, and pesticides as food and energy sources. These microbes convert contaminants into small amounts of water and harmless gases like carbon dioxide.
Bioremediation requires a combination of the right temperature, nutrients, and foods. The absence of these elements may prolong the cleanup of contaminants. Conditions unfavorable for bioremediation may be improved by adding “amendments” to the environment, such as molasses, vegetable oil, or simple air. These amendments optimize conditions for microbes to flourish, thereby accelerating the completion of the bioremediation process.
Bioremediation can either be done “in situ,” which is at the contamination site, or “ex situ,” which is at a location away from the site. Ex-situ bioremediation may be necessary if the climate is too cold to sustain microbe activity or if the soil is too dense for nutrient distribution. Ex-situ bioremediation may require excavating and cleaning the soil above ground, which may add high costs to the process.
The bioremediation process may take several months to several years, depending on variables such as the size of the contaminated area, the concentration of contaminants, temperature, soil density, and whether bioremediation will occur in situ or ex-situ.
Advantages of Bioremediation
Bioremediation offers numerous advantages over other cleanup methods. By relying solely on natural processes, it minimizes damage to ecosystems. Bioremediation often occurs underground, where amendments and microbes can be pumped to clean up contaminants in groundwater and soil. Consequently, bioremediation does not disrupt nearby communities as much as other cleanup methodologies.
Bioremediation creates relatively few harmful byproducts (mainly because contaminants and pollutants are converted into water and harmless gases like carbon dioxide). Finally, bioremediation is cheaper than most cleanup methods because it does not require substantial equipment or labor. By the end of 2018, the United States Environmental Protection Agency (EPA) had brought bioremediation activities to 1,507 sites.
Example of Bioremediation
In 1989, the Exxon Valdez oil tanker ran aground off Alaska’s coast; the tanker spilled approximately 11 million gallons of oil. Around this time, bioremediation was gaining traction as a viable option for oil cleanups. The EPA and Exxon Mobil Corporation (XOM) began testing different compounds. Initial tests regarding the effectiveness of bioremediation looked promising.
Between 1989 and 1990, more than 100,000 pounds of fertilizer were applied over more than 2000 applications to the affected areas. By mid-1992, the cleanup was complete, and the fertilizer had degraded nearly all the oil compounds.
What are the types of bioremediation?
In general, there are three types of bioremediation:
- Biostimulation: Microbes are stimulated to begin the remediation process via chemicals or nutrients that activate them.
- Bioaugmentation: Used mainly in cleaning up soil contamination, this process adds bacteria to the surface of the affected area, where they are allowed to grow.
- Intrinsic Bioremediation: Converts toxic materials into inert ones using the native microbiome of the affected area.
Is composting a form of bioremediation?
In a sense, yes. Composting can be seen as a form of bioremediation known as biodegradation that converts food waste into potable soil. This reduces the burden on landfills.
What is mycoremediation?
Mycoremediation is a bioremediation that relies on fungi rather than bacteria or other microbes to decontaminate affected areas.
Conclusion
- Bioremediation is a branch of biotechnology that uses living organisms, like microbes and bacteria, to decontaminate affected areas.
- It removes contaminants, pollutants, and toxins from soil, water, and other environments.
- Bioremediation is used to clean up oil spills or contaminated groundwater.
- Bioremediation may be done “in situ”—at the contamination site—or “ex-situ”—away from the site.
