Page 150 - Plant-Based Remediation Processes

Chapter 8
A Multi-disciplinary Challenge for
Phytoremediation of Metal-Polluted
Pyrite Waste

Teofilo Vamerali, Marianna Bandiera, and Giuliano Mosca

8.1 The Phytoremediation Concept Evolves in Pyrite

After the discovery of hyperaccumulators (Raskin et al. 1994; Salt et al. 1995),
plants which accumulate high above-ground levels of one or a few metals without
evident symptoms of toxicity, the application of plant-based technologies to rem-
edy metal-contaminated soils has received huge attention. Metalliferous soils
provide several hyperaccumulators, but their application must be verified carefully
in terms of biomass—generally very small—and uptake when plants are cultivated
out of their native environment (Brooks et al. 1977).
Phytoextraction consists of removing toxic elements through the harvestable
biomass, after sufficient translocation from roots has occurred. Although promising,
the method has some limitations due to difficult plant establishment, possible
limited soil metal availability, insufficient root uptake (exclusion), symplastic
mobility and xylem loading, as well as the great energy costs required for detoxifi-
cation and storage (Meagher 2000; Clemens et al. 2002).
The use of biomass species (trees and crops) may represent a realistic alternative
to hyperaccumulators for removing trace metals (Vamerali et al. 2010). Biomass
species can absorb a wider range of metals but at low concentrations, a feature
compensated by higher biomass productivity. The application of cultivated species
is facilitated by the easy availability of seeds and cuttings on the market, but their
adaptability and method of cultivation should be verified in each specific site. The
extended root system of trees is suitable for remediating especially deep polluted
layers (Pulford and Dickinson 2005) and short-rotation coppices of poplar (Populus

T. Vamerali (*)
Department of Food Sciences, University of Parma, Viale G.P. Usberti 11/A, 43100 Parma, Italy
e-mail: teofilo.vamerali@unipd.it
M. Bandiera • G. Mosca
Department of Agronomy, Food, Natural Resources, Animals and the Environment, University of
Padova, Viale dell’Universita ` 16, 35020 Legnaro (Padova), Italy

D.K. Gupta (ed.), Plant-Based Remediation Processes, Soil Biology 35, 141
DOI 10.1007/978-3-642-35564-6_8, # Springer-Verlag Berlin Heidelberg 2013