Bioremediation by Bacteria: Snacking on Gasoline

Bioremediation by Bacteria: Snacking on Gasoline

By Sofia Elizondo

Pollution by gasoline is a widespread issue. Surface spills and leaks coming from gasoline storage tanks located underground have affected a part of the earth called the vadose zone. This region, also known as the unsaturated zone, is located between the land surface and the water table – as shown in the figure below:

The fractions of gasoline that reach these parts of the earth are sometimes toxic or considered cancer-causing agents, which is why removal of gasoline pollutants is necessary. Bacteria have been identified as effective organisms for breaking down and consuming these pollutants, a process known as bioremediation. In a recent study, a system was set up in order to observe how effective bioremediation can be in the vadose zone based on manipulation of water availability and nutrient content. The vadose zone monitoring system (VMS) was placed beneath a gas station, where gasoline pollutants often sink into the soil.

It was found that under conditions of sufficient water and nutrients, there was reduction of various gasoline pollutants – meaning removal by bacteria was an effective means of revitalizing the vadose zone of polluted areas. However, a cost or trade-off of this system is that it requires constant intervention by humans as opposed to being completely natural remediation. Nevertheless, under the correct conditions and with the appropriate resources, bioremediation may be employed to diminish gasoline pollutants.

Reference

Moshkovich, E., Ronen, Z., Gelman, F., and Dahan, O. 2018. In situ bioremediation of gasoline-contaminated vadose zone: implications from direct observations. J. Environ. Qual. 17:1-11.