Green remediation strategies to improve the quality of contaminated soils

Abstract

Soil contamination has been identified as an important issue requiring action for soil protection in Europe. New approaches to remediation will be required if soils are to perform their essential functions. There is a need to find new strategies of remediation which, to date, have involved rather drastic technologies or landfill disposal. The US EPA is promoting strategies (green remediation) that restore contaminated sites to productive use with great attention paid to global environmental quality, including the preservation of soil functionality. As an example of this approach, a case study is reported in which phytoremediation as a ‘green remediation strategy’ has been selected to clean-up sites contaminated by polycyclic aromatic hydrocarbons (PAHs). Lupinus albus and Zea mays were tested and the efficiency of the remediation was determined comparing the decrease in PAH concentration in soil with and without plants growing (32 and 22%, respectively). This is a consequence of the presence of plants that stimulated the microbial biomass involved in PAH degradation. As an index of soil quality at the end of the phytoremediation test, soil stability structure was evaluated by means of wet aggregate stability (WAS). This parameter sharply increased from 35 to 60% after cultivating selected plants.

Keywords:

• green remediation
• phytoremediation
• PAHs
• plants
• soil

Acknowledgements

The authors thank Irene Rosellini for technical assistance.