The main difference between bioaugmentation and biostimulation is that bioaugmentation is the introduction of microorganisms into the environment to achieve bioremediation, whereas biostimulation is the stimulation of the naturally-occurring microorganisms for bioremediation.
Bioaugmentation and bioremediation are the two techniques of bioremediation in which contamination is removed from soil and water. They use living organisms to remove harmful pollutants from contaminated areas.
Key Areas Covered
1. What is Bioaugmentation
– Definition, Features, Importance
2. What is Biostimulation
– Definition, Features, Importance
3. Similarities Between Bioaugmentation and Biostimulation
– Outline of Common Features
4. Difference Between Bioaugmentation and Biostimulation
– Comparison of Key Differences
Key Terms
Bioaugmentation, Biostimulation
What is Bioaugmentation
Bioaugmentation is the introduction of exogenous microorganisms for the removal of pollutants from soil and water. These microbial strains are well-characterized for the removal of pollutants. They are supplements to increase the degradation capacity of pollutants. Before the introduction of microorganisms to the site of pollution, several tests are to be performed, including the chemical structure and the concentration of pollutants, nature and the size of the indigenous microorganisms, physical properties of the environment including the soil pH, soil type, porosity, hydraulic conductivity, etc.
Figure 1: Bioaugmentation
Furthermore, archaea or bacterial cultures can be used as microorganisms to remove pollutants. Bioaugmentation is important when the natural microorganisms in the soil and water are inefficient and slow in removing pollutants. In bioaugmentation, exogenous microorganisms metabolize pollutants during their metabolism. It enhances the degradation of chemicals. It is commonly used in municipal wastewater treatment to activate sludge bioreactors. B. licheniformis, P. polymyxa, B. stearothermophilus, Flavobacterium, B. thuringiensis, Penicillium sp., Aspergillus sp., Pseudomonas, Arthrobacter, Streptomyces, Saccharomyces, etc., are the types of microorganisms use in bioaugmentation. However, it increases the efficiency and speed of removing biodegradable pollutants from the soil and water.
What is Biostimulation
Biostimulation is the removal of pollutants from soil and water by inducing the indigenous microorganisms by adding nutrients required by the indigenous microorganisms. Hence, it motivates indigenous microorganisms to consume pollutants. Sometimes, it may take decades to remove pollutants by indigenous microorganisms. Therefore, the efficiency of the degrading pollutants is slow. Also, the time can be reduced by adding nutrients to the site of pollution. On the other hand, nutrients that can be added to the pollution site can be carbon, oxygen, nitrogen, and phosphorus.
Figure 2: Biostimulation
Moreover, biosparging and bioventing are examples of biostimulation. Biosparging is the injection of air into the saturated zone of the soil matrix or groundwater to stimulate biodegradation. In comparison, bioventing is the injection of high-pressure air (oxygen) into the unsaturated soil to enhance biodegradation.
Similarities Between Bioaugmentation and Biostimulation
- Bioaugmentation and biostimulation are two techniques of bioremediation.
- They are responsible for the removal of pollutants from soil and water.
Difference Between Bioaugmentation and Biostimulation
Definition
Bioaugmentation refers to the addition of archaea or bacterial cultures required to speed up the rate of degradation of a contaminant. In contrast, biostimulation refers to the modification of the environment to stimulate existing bacteria capable of bioremediation.
Type of Microorganisms
Bioaugmentation uses well-characterized bacteria, while biostimulation uses naïve microorganisms.
Type of Environment
Bioaugmentation is suitable for various in-situ and ex-situ methods along with mechanical mixing, while biostimulation is not suitable for tight, impermeable surfaces.
Addition
Exogenous bacteria are added in bioaugmentation, while nutrients are added in biostimulation.
Types of Pollutants
Bioaugmentation can remove all ranges of petroleum contaminations and chlorinated solvents, while biostimulation can degrade low-level hydrocarbon contaminations.
Most Preferred
Bioaugmentation is preferred for cost-effective bioremediation, while biostimulation is preferred for long-term monitoring sites.
Conclusion
In brief, bioaugmentation and biostimulation are two bioremediation techniques for removing pollutants from soil and water. Bioaugmentation is the addition of exogenous microorganisms to the site of pollution. Importantly, they are well-characterized organisms. Also, bioaugmentation is suitable for various in-situ and ex-situ methods to remove pollutants, and it can remove all ranges of petroleum contaminations. Additionally, it is a cost-effective method of bioremediation. In comparison, biostimulation is the use of naturally-occurring organisms to remove pollutants. Therefore, it uses naïve microorganisms, and nutrients need to be supplied. However, it is not suitable for tight, impermeable surfaces. But, biostimulation is effective for removing low-level hydrocarbons, and it is preferred for long-term monitoring sites. Therefore, the main difference between bioaugmentation and biostimulation is their features.
References:
- Bioaugmentation. Bioaugmentation – an overview | ScienceDirect Topics. (n.d.).
- Biostimulation. Biostimulation – an overview | ScienceDirect Topics. (n.d.).
Image Courtesy:
- “Illustration of relevant processes in the ATES-ENA system” By Timmer26 – Own work (CC-BY SA 4.0) via Commons Wikimedia
- “Biodegradation of Pollutants” By Zhuobiao Ni – Own Work (CC-BY SA 4.0) via Commons Wikimedia
Leave a Reply