Bioremediation: The Inexpensive, Organic Remediation Method
What’s the process?
Bioremediation involves the use of tiny organisms, called microbes, to help clean up contaminated soil and groundwater. These living organisms (usually some type of bacteria) feed off of the contaminants (such as solvents, oil and petroleum products, and pesticides) in or on a site.
When the microbes eat these contaminants, they will eventually digest and metabolize them, at which point the contaminants will be changed into water or harmless gases, like ethene, or carbon dioxide.
The technique of “bioaugmentation” is the adding of the correct amount of microbes, and the fostering of their growth, to ensure a site can be fully cleared by the organic process.
For the right amount of microbes to grow, “amendments” may have to be pumped into the zone through wells, such as vegetable oil or molasses. This is to ensure that the microbes first have nutrients and do not immediately die off, as conditions must be amenable to the living microbes for successful bioremediation to take place.
Similarly, the temperature should not be too cold, and the right amount of nutrients must be present for the microbes to multiply and more quickly eat away at the contamination. However, if these conditions cannot be met on-site, the EPA recommends that excavation of the soil or groundwater should be carried out ex situ (off-site, or above ground).
To bioremediate contaminated groundwater, wells must be dug so the water can be pumped to above-ground tanks, where amendments should be added. Then the amendment-rich water will be pumped directly back into the ground, which allows the microbes to do their job in the rest of the contaminated groundwater. (Yet some groundwater sites may require the use of a ex situ bioreactor for remediation to occur.)
Bioremediation could take anywhere from a few months to several years to clean up 100% of the contamination. Some factors which can alter the duration of the process are,
- the conditions of the site,
- the spread or concentration of the contamination, and
- whether the remediation occurs on-site or off-site.
The first reason you might choose bioremediation over other options is that it’s safe. The nutrients or amendments added to help the microbes grow are no more toxic than typical lawn fertilizers, and the microbes die off once the contamination has been completely dispatched.
To help ensure safety, companies that specialize in bioremediation will take and test samples of the soil or groundwater regularly. And since the contaminants are turned into water or benign gasses, no secondary clean up is necessary.
Bioremediation can help keep costs down by avoiding the need for expensive excavation or pumping. This is because most jobs are done in situ, on on-site. Disturbances to the nearby communities are also minimized because of the lack of truck traffic and large, daily crews to-and-from the site.
Bioremediation is also a proven method environmental remediation, it is now being used in over a hundred Superfund sites, and in other contaminated areas all across the nation.
If you would like to know more about bioremediation or other remediation techniques, please give Environmental Remediation Experts a call at (888) 995-2143 to speak with an expert today or click here to email us.
Photo credit: EPA.gov