Bioremediation

The Bioremediation Process

Bioremediation allows natural processes to clean up harmful chemicals in the environment. Microscopic "bugs" or microbes that live in soil and groundwater like to eat certain harmful chemicals, such as those found in gasoline and oil spills. When microbes completely digest these chemicals, they change them into water and harmless gases such as carbon dioxide. In order for microbes to clean up harmful chemicals, the right temperature, nutrients (fertilizers), and amount of oxygen must be present in the soil and groundwater. These conditions allow the microbes to grow and multiply-and eat more chemicals. When conditions are not right, microbes grow too slowly or die. Or they can create more harmful chemicals. One way they improve conditions is to pump nutrients or other inferior substances (such as molasses) underground. Sometimes microbes are added if enough aren't already there. The right conditions for bioremediation cannot always be achieved underground. At some sites, the weather is too cold or the soil is too dense. At such sites, we might dig up the soil to clean it above ground where heaters and soil mixing help improve conditions. After the soil is dug up, the proper nutrients are added. Oxygen also may be added by stirring the mixture or by forcing air through it. However, some microbes work better without oxygen.

With the right temperature and amount of oxygen and nutrients, microbes can do their work to "bioremediate" the harmful chemicals. Sometimes mixing soil can cause harmful chemicals to evaporate before the microbes can eat them. To prevent these chemicals from polluting the air, we mix the soil inside a special tank or building where chemicals that evaporate can be collected and treated. Microbes can help clean polluted groundwater as well as soil. To do this, we drill wells and pump some of the groundwater into tanks. Here, the water is mixed with nutrients and air before it is pumped back into the ground. The added nutrients and air help the microbes bioremediate the groundwater. Groundwater can also be mixed underground by pumping nutrients and air into the wells. Once harmful chemicals are cleaned up and microbes have eaten their available "food," the microbes die.

• A Citizen's Guide to Bioremediation
• Click here for an EPA Overview on Bioremediation of Chlorinated Solvents

The Adventus Bioremediation Advantage

The time it takes to bioremediate a site depends on several factors:

• types and amounts of harmful chemicals present
• size and depth of the polluted area
• type of soil and the conditions present
• whether cleanup occurs above ground or underground

These factors vary from site to site. Adventus products are 50% less expensive than Regenesis offerings, such HRC, HRC-X, and ORC. They are also longer lasting, and do not allow the creation of problematic intermediates. It can take a few months or even several years for microbes to eat enough of the harmful chemicals to clean up the site. EPA uses bioremediation because it takes advantage of natural processes. Polluted soil and groundwater can be cleaned at the site without having to move them somewhere else. If the right conditions exist or can be created underground, soil and groundwater can be cleaned without having to dig or pump it up at all. This allows cleanup workers to avoid contact with polluted soil and groundwater. It also prevents the release of harmful gases into the air. Because microbes change the harmful chemicals into water and harmless gases, few if any wastes are created. Often bioremediation does not require as much equipment or labor as most other methods. Therefore, it is usually cheaper. Bioremediation has successfully cleaned up many polluted sites and is being used at 50 Superfund sites across the country.

Adventus Bioremediation Solutions and Products

DARAMEND® and TERRAMEND™ for ex situ, on-site treatment of soil and sediment impacted by recalcitrant organic compounds (high molecular weight PAHs, pesticides). Performance guaranteed.

EHC® technologies for in situ chemical reduction (ISCR) of chlorinated solvents, pesticides and heavy metals.

mGCW systems for in situ treatment of groundwater impacted by volatile organic compounds (refined petroleum hydrocarbons, chlorinated solvents).

Permeable reactive barrier (PRB) technology using zero-valent iron (ZVI) for the remediation of groundwater impacted by chlorinated solvents.

ISGS for In Situ Geochemical Stabilization of DNAPL for the purposes of source removal and flux reduction to facilitate enhanced passive remediation (accelerated natural attenuation) of dissolved plumes.

Adventus Bioremediation Case Studies

Adventus has successfully treated sites contamination with the following hazardous materials:

Dichloromethane Carbon Tetrachloride Chloroform Chloroform Tetrachloroethylene

Tetrachloroethylene Trichloroethylene 1,1-dichloroethene Pentachlorophenol

1,1,1-Trichloroethane 1,1,1-Trichloroethane 1,1-Dichloroethane Perchlorate

Explosives1 TNT RDX HMX DNT Nitroglycerine Amino-DNTs Nitrobenzene PETN Tetryl TPHs (entire range) Phthalates Total Chlorophenols Pentachlorophenol Total PAHs HMW PAHs2

Pesticides3 Toxaphene DDT DDD DDE Lindane Chlordane Total HCHs Dieldrin Aldrin Endrin Ketone 2,4,5-T 2,4-D Metalochlor Silvex

Interested In an Environmental Site Assessment? Contact Us For A Free Site Evaluation