Tuesday, September 6, 2011

Groundwater Treatment - Groundwater Remediation

There is a wide range of contaminants found in groundwater. Groundwater remediation is the process of removing pollutants and contaminants from it. This is applied using various techniques thereby making it safe for consumption. These techniques include chemical, biological and physical treatment technologies. A combination of technologies is often used in the treatment.

Just a few biological techniques include:

Phytoremediation: Certain plants and trees are planted where the roots can access ground water. Over time they absorb contaminants and are then destroyed. The movement of water disperses the pollutants over a wide area which can then come into contact with groundwater wells making surface water (like springs) hazardous to humans and animals. The study of this movement is called hydrogeology.

Bioventing: The use of microorganisms to biodegrade organic constituents absorbed in the groundwater.

Biosparging: Uses indigenous microorganisms to biodegrade constituents.

Bioslurping: Combines part of bioventing and vacuum pumping to retrieve the product from the groundwater and soil.

Bioaugmentation: The inoculation of strains which degrade the contaminants.

A few chemical techniques include:

Chemical precipitation: Addition of an agent to a container of water which is stirred to create a reaction.

Carbon absorption: Activated carbon absorbs volatile organic compounds.

Ion exchange: Water passing downward under pressure through a granular medium.

Ozone and oxygen gas injection: Ozone and oxygen is injected into soil and groundwater contamination resulting in surfactant enhanced recovery and aqueous chemical oxidation.

Some examples of physical treatment techniques are:

Air sparging: Blowing air directly into the ground water creating bubbles at the surface. The contaminants are removed by contact with the air.

Dual phase extraction: Using a high-vacuum system to remove both contaminated groundwater and soil vapour.

Pump and treatment: This is one of the most widely used groundwater remediation technologies. The ground water is pumped to the surface where it is treated either chemically or biologically to remove contaminants.

Groundwater treatment is a highly effective weapon in the modern fight for more clean water.