Match the environmental remediation method to its description.
soil vapor extraction
air sparging
bioventing
natural attenuation
Air is bubbled through groundwater to
remove volatile organic pollutants.
Natural processes break down the
pollutants.
Air is circulated through perforated
pipes in the contaminated soil.
Air is pumped into or out of soil to
supply oxygen to microbes.

1) soil vapor extraction

Air is circulated through perforated  pipes in the contaminated soil.

2) air sparging  Air is bubbled through groundwater to  remove volatile organic pollutants.

3) bioventing   Air is pumped into or out of soil to  supply oxygen to microbes.

4) natural attenuation Natural processes break down the  pollutants.

Explanation:

Soil vapor extraction  is a method in which air is circulated through perforated pipes in the contaminated soil for the cleaning of soil from pollutants. Air sparging is a remediation technique in which air is bubbled through groundwater to  remove volatile organic pollutants present in water bodies. Bioventing  is a process in which air is pumped into or out of soil to  supply oxygen to microbes which helps in the decomposition process. Natural attenuation is a natural processes which helps in break down the  pollutants present in the soil.

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