D.**Bioaugmentation**

Bioaugmentation is arrangement to enrich the existing microorganism population and make it more effective in reducing the level of contamination. This technique refers to the addition of organic culture to the contaminated soil and make environment of the site similar to a bioreactor. There are two common options can be used one is addition of a pre-adapted pure bacterial strain and second is addition of a pre-adapted consortium to the contaminated site. Bioaugmentation is mainly used in oil contaminated site for bioremediation. Bioaugmentation is a low-cost method in comparision of other methods of treating wastewater and soil contamination [20].
