Coupling Phytoremediation with Plant Biomass Valorisation and Metal Recovery: an Overview

Phytoremediation/phytoextraction is a plant-based technology widely applied for the removal of potentially toxic elements (PTEs) such as heavy metals, from contaminated soils. Basically, the plants used in the phytoextraction process are able to bioaccumulate metals in their roots and, depending on the ability of the plant to uptake the pollutants along with other influencing factors, metals can be further translocated from roots to the aerial parts of the plant. The main drawback of phytoextraction is associated with the resulted waste biomass which is identified as a secondary pollutant due to its high metal content. The resulted biomass can create further pollution problems, so additional treatment such as incineration, composting, pyrolysis and either direct disposal can be applied to treat contaminated biomass resulted from phytoextraction. The main objective of the present paper is to discuss the possibility of integrating phytoremediation with plant biomass valorization and metal recovery as promising alternatives instead of direct disposal of waste biomass.