Five ways scientists can make soil less dirty

May 24, 2016

Hello BEST community,

This week the Bioenergy & Sustainability School is taking a look into the remediation of soil and water contaminants. In the week thus far we've taken a look at remediation/ removal of uranium and lead from soil and water. Today, we take a broader approach.

The process of "cleaning" soil or water is far from straightforward. Every new source of contamination requires a slightly different methodology. Be it from heavy metals, oil, pesticides, or anything else, the same approach will not solve all problems.  Case and point, if an oil spill were to occur on soil, then a method of soil remediation known as "Air Sparging" would be utilized due to the ease with which the oil could be evaporated. Air sparging involves the movement of air through the soil or groundwater to promote evaporation of the contaminant. This method does not require the removal of the soil, a type of remediation known as in-situ remediation. 

In-situ remediation tends to be more environmentally friendly, due to the soil not needing to be removed/ replaced. However, not all contaminants can be evaporated out. For example, a far different approach would be needed for heavy metal remediation. If groundwater were to become contaminated with heavy metal then the groundwater would need to be removed for filtration. This would be an ex-situ remediation technique. An example of which is air stripping, which involves collecting groundwater and filtering air through it to remove contaminants. Be it in-situ or ex-situ, different approaches will need to be used for different situations depending on the contaminant, or location.

Joshua Goff

Undergraduate Intern

2016 BioEnergy & Sustainability School

Soil and Water Science Department

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