When soil pollution cannot be prevented, bioremediation techniques are essential to cleanup contaminated sites to prevent further environmental pollution and human health risks. There are a variety of bioremediation techniques depending on the pollutant, its contamination level and the objective of the remediation.
Bioremediation is an in situ strategy, where soils remain in the ground during treatment. It utilizes soil microorganisms such as bacteria, fungi and plants to degrade, remove or reduce soil pollutants from the environment, including petroleum hydrocarbons, solvents, and pesticides. It is a cost-effective and eco-friendly solution compared to other engineering techniques such as using mechanical, thermal or chemical means, although might be more time-consuming to reach the remediation objective. It may also be hard to monitor, given that there is less certainty about the treatment's uniformity as environmental variability can affect the efficiency of the remediation process.
Bioremediation is also a nature-based technology, harnessing soil-dwelling organisms to biodegrade the contaminants. Soils polluted with trace elements can be remediated by immobilizing the trace elements and reducing their bioavailability. Trace elements are converted into another form with less toxic chemical and biological properties. Soils polluted with chromium sulfate from the leather industry can be converted from hexavalent chromium to its trivalent state, which is less mobile and less hazardous (FAO, 2021).
Source: Cornell News
There are promising (and cool!) scientific discoveries of microorganisms that can assist with soil bioremediation. Recently, researchers at Cornell discovered a new species of bacteria called Paraburkholderia madseniana that breaks down organic pollutants released from petrochemical plants known as polycyclic aromatic hydrocarbons (PAHs). The bacteria can degrade these aromatic compounds.
References
FAO and UNEP. (2021). Global assessment of soil pollution: Report. Chapter 13: Actions to Tackle Soil Pollution. https://doi.org/10.4060/cb4894en
Newly found bacteria fights climate change, soil pollutants. (2020). Cornell Chronicle. Retrieved from https://news.cornell.edu/stories/2020/02/newly-found-bacteria-fights-climate-change-soil-pollutants
Technology Networks. (2020, February 21). Bacteria That Could Help Combat Soil Pollution. From Technology Networks. https://www.technologynetworks.com/immunology/news/bacteria-that-could-help-combat-soil-pollution-331116
Verma, A. (2021). Bioremediation Techniques for Soil Pollution: An Introduction. IntechOpen. https://doi.org/10.5772/intechopen.99028