*5.4.1 In-situ bioremediation techniques*

These techniques comprise treating polluted substances at the pollution site. It does not need any excavation and by little or no disturbance in soil construction. Perfectly, these techniques should to be cost effective compared to ex-situ bioremediation techniques. Some in-situ bioremediation techniques like bioventing, biosparging and phytoremediation may be enhanced, while others may be progress without any form of improvement such as intrinsic bioremediation or natural attenuation. In-situ bioremediation techniques have been effectively used to treat chlorinated solvents, heavy metals, dyes, and hydrocarbons polluted sites [22–24].
