Biological treatment offers the best environmental friendly method for remediating hydrocarbon and heavy metal contaminated soil because it utilized the capability of the indigenous microorganisms in the soil environment to break down the hydrocarbons and heavy metals into innocuous substances.

There is no right answer to your question. The selection of the most appropriate remediation technology depends on the specific conditions at the contaminated site. Therefore, before selecting the most appropriate remediation technology, it is first necessary to conduct a survey and evaluate the matrices from which the contamination is to be removed, the availability and distribution of the contamination, the rate of sorption of the pollutants and many other parameters that provide information for deciding what the most appropriate remediation technology will be.

Best regards

Vit

https://uwe-repository.worktribe.com/OutputFile/1788456

you can see this paper

We have different methods used to remediate polluted soils including; thermal remediation, bioremediation, phytoremediation etc depending on the condition of the impacted site. You can also read the attached materials

Advanced bioremediation techniques ( eg. use of indigent microbes to break down the Petroleum hydrocarbons and other compounds) have proven to be useful in oil spill clean ups and remediation for hydrocarbon impacted sites in recent time. However, these methods are subject to the outcome of certain preliminary investigations which will determine the extents/mode of distribution, nature of the impacts, and other factors.