By Dulara Kuruppu
With the advent of industrialization and a surging demand for standardized living conditions, it has become more important than ever that we clean up after ourselves. The detrimental effects of our activities have become clearer in recent times, highlighting the importance of implementing an environmentally friendly clean-up solution. This solution comes in the form of an engineered technology known as ‘bioremediation’.
Bioremediation, in the simplest forms, is the usage of microorganisms such as bacteria and fungi to eliminate contaminants, pollutants and toxins in the environment. It has become most useful in current times due to threats arising from modern-day commercial undertakings, including oil spillages and eutrophication, and provides a sustainable method to treat sewage.
The process of bioremediation, simplified.
Bioremediation in Oil Spillages
An important example of the use of bioremediation to clean up oil spills can be seen in the Deepwater Horizon (DWH) oil spill, which left the oil from 4.9 million barrels and 250, 000 metric tons of natural gas on the Gulf of Mexico for almost three months. Researchers from the Gulf of Mexico Research Initiative (GoMRI) discovered that microbes in the water move towards the hydrocarbons (compounds made of carbon and hydrogen atoms, like crude oil and natural gas) and consume them. In the process, they convert them into by-products that are left to be broken down by other organisms.
Due to the frequency of oil spillages in areas such as the Gulf of Mexico, samples of microbes more commonly have the genes for hydrocarbon degradation, making up for 90% of the microbial community. Similar patterns are seen in the seafloor and salt marshes, where microbes undergo anaerobic hydrocarbon degradation due to depleted supplies of oxygen. This is the process of bioremediation in the absence of oxygen, and decomposes pollutants found in the water.
Bioremediation in Treating Rivers, Streams and Estuaries
Eutrophication is the excessive plant and algal growth in water bodies due to an increased availability of nutrients needed for photosynthesis. This fertility of the ecosystem results in the formation of algal blooms, which are sheets of algae and other microorganisms that spread across the surface of the water, preventing the penetration of light or oxygen through to other organisms underwater. It is accelerated by human activities, which introduces sewage, fertilizers and other sources of nutrients into the water, and is known as cultural eutrophication. This consequently results in considerable decline in freshwater resources, fisheries and recreational water bodies.
As a result, bioremediation is extremely beneficial in situations like these, as was found by a study conducted on the effects of bioremediation on a eutrophic lake. This is an example of in situ bioremediation, where the treatment is carried out in the soil or groundwater. Besides being very efficient and environmentally friendly, the bacterial preparation added to the eutrophic water body purified it, decreased its turbidity (the level of clarity in a water sample) and inhibited algae growth. Over time, this method proves to be a cost-effective solution to clearing eutrophic water bodies, and thus improves the water quality and allows underwater organisms to repopulate.
Bioremediation in Sewage Treatment
Untreated wastewater is also a serious socioeconomic issue. According to the United Nations, around 1.8 billion people, which is almost 23% of our current population, drink water that is contaminated with fecal matter. This can lead to diseases such as dysentery, typhoid and polio, making it critical that we find an efficient way to treat wastewater.
In fact, sewage treatment plants are among the greatest bioremediation enterprises in the world. The in situ process of bioremediation encourages microbes to degrade contaminants through the addition of amendments, known as biostimulation. It may also involve bioaugmentation, where select strains of bacteria are manually added to supplement the microbial population and enhance the rate at which bioremediation occurs. Increasing the concentration of active microorganisms within the treatment environment speeds up the process. The most efficient way to do this is aerobic bioremediation, where oxygen is used up by the microbes. It is optimized by the direct addition of oxygen, or chemical oxidants that break down to release oxygen.
Research suggests that compared to many other methods of wastewater treatment, bioremediation comes out on top as the most effective and economic solution to be used.
Bioremediation serves to enhance many aspects of our modern-day operations, and through further evaluation of this scientific technology, we can hope to discover more feasible uses for it in the future.
Sources
Bioremediation: Types, Uses and Techniques | Earth Eclipse. 22 Mar. 2019, https://eartheclipse.com/energy/bioremediation-types-uses-techniques.html. Accessed 21 Apr. 2023.
Eutrophication | Definition, Types, Causes, & Effects | Britannica. https://www.britannica.com/science/eutrophication. Accessed 21 Apr. 2023.
“How Microbes Clean up Oil: Lessons From the Deepwater Horizon Oil Spill.” ASM.Org, https://asm.org:443/Articles/2020/April/How-Microbes-Clean-up-Oil-Lessons-From-the-Deepwat. Accessed 21 Apr. 2023.
Shan, Mingjun, et al. “Study on Bioremediation of Eutrophic Lake.” Journal of Environmental Sciences, vol. 21, Jan. 2009, pp. S16–18. ScienceDirect, https://doi.org/10.1016/S1001-0742(09)60027-9. Accessed 21 Apr. 2023.
Society, Microbiology. Bioremediation: The Pollution Solution? https://microbiologysociety.org/blog/bioremediation-the-pollution-solution.html. Accessed 21 Apr. 2023.
US EPA, OLEM. Introduction to In Situ Bioremediation of Groundwater. 22 Apr. 2015, https://www.epa.gov/remedytech/introduction-situ-bioremediation-groundwater. Accessed 21 Apr. 2023.
“Water Pollution Statistics 2022-2021 and 2019-2018 - Ocean Pollution Facts.” GlobeWater, 22 Oct. 2018, https://www.globewater.org/facts/water-pollution-statistics/. Accessed 21 Apr. 2023.
“What Is Bioremediation, and How Does It Work (With Examples)?” Investopedia, https://www.investopedia.com/terms/b/bioremediation.asp. Accessed 21 Apr. 2023.