Polycyclic aromatic hydrocarbons and heavy metal contaminated sites: Phytoremediation as a strategy for addressing the complexity of pollution

Since the industrial revolution, soil has been increasingly subjected to continuous negative pressure, largely determined by human activities, which have dispersed heavy metals and many persistent organic compounds causing severe soil contamination. Among pollutants, heavy metals and polycyclic aromatic hydrocarbons (PAHs), which are ubiquitous and generated also from natural resources, are of particular concern. The simultaneous presence of both kinds of pollutants is very common in brownfield sites, and the clean-up of these areas presents technical difficulties and requires appropriate solutions at a reasonable cost. Remediation technologies have often used invasive processes that greatly damage soil characteristics, causing the deterioration of this important resource. In this chapter, the objectives are to briefly examine the processes involved in heavy metal and PAH reactions in soil in order to evaluate the best possible cost-effective remediation strategies for maintaining a high quality of soil and surrounding environment.