Question

Which of the following is an example of in-situ bioremediation?

• A. Pumping contaminated groundwater to the surface for treatment
• B. Excavating contaminated soil and treating it in a bioreactor
• C. Injecting microorganisms directly into the contaminated site
• D. Spraying chemical agents onto polluted surfaces

Hint:

• In-situ bioremediation Treatment occurs at the contaminated site itself (e.g., bioventing, biosparging, bioaugmentation by injection). Latin "in situ" means "in the original place."
• Ex-situ bioremediation Contaminated material is excavated/removed and treated elsewhere (e.g., landfarming, biopiles, bioreactors). Latin "ex situ" means "out of place."

Answer 1

The Correct Option is C

In-situ bioremediation involves treating the contamination at its source without removing the contaminated materials. Out of the given options:

Pumping contaminated groundwater to the surface for treatment: This is not in-situ as it involves extraction of water.

Excavating contaminated soil and treating it in a bioreactor: This involves moving the soil, thus not in-situ.

Injecting microorganisms directly into the contaminated site: This is an example of in-situ bioremediation because it treats the contaminants at their site without moving them.

Spraying chemical agents onto polluted surfaces: This method is ex-situ when the chemical application changes the site boundaries for contaminant treatment.

Therefore, the correct answer is: Injecting microorganisms directly into the contaminated site.