The key difference between bioaugmentation and biostimulation is that bioaugmentation is the addition of specific cultured microorganisms into contaminated soil or groundwater for the purpose of biodegradation of contaminants. Meanwhile, biostimulation is the modification of the environment by adding nutrients, electron donors and electron acceptors to stimulate existing microorganisms, especially bacteria that are capable of biodegradation.
Contamination of soil and water is a big environmental problem. Chemicals are used to treat contaminated water bodies. Similarly, different methods are used to degrade contaminants in the soil. Biodegradation is a natural process that is done by microorganisms. Bioaugmentation and biostimulation are two practices that utilize microorganisms that are capable of degrading contaminants to purify contaminated areas. In bioaugmentation, cultured microorganisms are added to the contaminated environment while in biostimulation, existing microorganisms are stimulated to promote degradation.
CONTENTS
1. Overview and Key Difference
2. What is Bioaugmentation
3. What is Biostimulation
4. Similarities Between Bioaugmentation and Biostimulation
5. Side by Side Comparison – Bioaugmentation vs Biostimulation in Tabular Form
6. Summary
What is Bioaugmentation?
Bioaugmentation is the practice of adding cultured microorganisms, especially archaea and bacteria, into contaminated soil or water in order to biodegrade contaminants. These microbes are specific microorganisms identified as microorganisms that are capable of degrading specific target contaminants. They increase the rate of degradation of contaminants. Therefore, bioaugmentation is used in many processes: to accelerate the reductive dechlorination process, achieve remediation targets, and realize cost savings. Due to adding of cultured microorganisms, the microbial population at the site increases. Moreover, it improves the cleanup process and reduces the time and cost of the degradation process.
Bioaugmentation is commonly practised in the municipal wastewater treatment plants. Microbes are added to activated sludge bioreactors in order to enhance the breakdown of contaminants. Not only that, bioaugmentation is important in clearing fuel contaminations, especially petroleum spills in soil and water.
Figure 01: Biodegradation of Pollutants
Since we are introducing cultured microorganisms into an environment that is new to them, their establishment is somewhat problematic and the success of the biodegradation process is also doubtful. However, many studies have shown the success of bioaugmentation. Moreover, scientists have discovered methods to increase the persistence and activity of exogenous microorganisms used in bioaugmentation. And, this has been receiving much attention currently in many bioremediation processes in contaminates sites.
What is Biostimulation?
Biostimulation is the stimulation of the existing microorganisms in an environment to promote the biodegradation process. In a biostimulation process, the environment is modified in order to stimulate native microorganisms. It is done mainly by adding nutrients such as phosphorus and nitrogen to a contaminated environment to stimulate the growth of the microorganisms. In addition, some electron acceptors and electron donors can be added into that particular environment.
Moreover, biostimulation can be enhanced by the bioaugmentation or the addition of exogenous microorganisms in order to increase the microbial population in the site. However, the biostimulation process needs prior knowledge of the microbes that are present and their in situ activities.
What are the Similarities Between Bioaugmentation and Biostimulation?
- Bioaugmentation and biostimulation are two sustainable treatment methods to clean polluted areas.
- Biostimulation can be enhanced by bioaugmentation.
- In both processes, microorganisms are utilized.
- Both methods are biological methods.
- These methods do not result in toxic byproducts and are not harmful, unlike chemical methods.
- Both methods have received much attention nowadays due to their potential and sustainability.
- They are promising and long-term solutions for the degradation of contaminated soil and water.
- Moreover, they are cost-effective methods, unlike chemical methods.
What is the Difference Between Bioaugmentation and Biostimulation?
Bioaugmentation is the process of adding specific microorganisms to enhance the existing populations and promote biodegradation process while biostimulation is the process of adding electron acceptors, electron donors, or nutrients to stimulate naturally occurring microbial populations in the contaminated area. So, this is the difference between bioaugmentation and biostimulation.
Moreover, in bioaugmentation, exogenous microorganisms are mainly used, while in biostimulation, indigenous microorganisms are used. Therefore, this is another difference between bioaugmentation and biostimulation.
Summary – Bioaugmentation vs Biostimulation
Bioaugmentation is the introduction of specific microorganisms into the contaminated areas in order to accelerate the biodegradation process. In contrast, biostimulation is the modification of the environment by adding nutrients, electron donors and acceptors to stimulate existing microorganisms to promote biodegradation process. In bioaugmentation, microbes are added, while in biostimulation, nutrients and other materials are added to stimulate existing microbes. So, this is the key difference between bioaugmentation and biostimulation. Both methods are considered as sustainable, cost-effective and eco-friendly methods in treating polluted areas.
Reference:
1. Nzila, Alexis, et al. “Bioaugmentation: An Emerging Strategy of Industrial Wastewater Treatment for Reuse and Discharge.” International Journal of Environmental Research and Public Health, MDPI, 25 Aug. 2016, Available here.
2. Gopinath, Ramdas, and Gerald K. “Biostimulation for the Enhanced Degradation of Herbicides in Soil.”Applied and Environmental Soil Science, Hindawi, 15 Sept. 2011, Available here.
Image Courtesy:
1. “Biodegradation of Pollutants” By Timmer26 – Own work (CC BY-SA 4.0) via Commons Wikimedia