Page 185 - Plant-Based Remediation Processes

Chapter 10
Phytostabilization as Soil Remediation Strategy

Agustina Branzini and Marta S. Zubillaga

10.1 Anthropogenic Pollution with Heavy Metals

Heavy metals are natural components of the Earth’s crust, being ubiquitous in low
amounts in terrestrial ecosystem. High natural levels of metals originating from
geological processes are occasionally found, but in many terrestrial ecosystems the
concentration of several heavy metals has reached toxic levels as a consequence of
anthropogenic activities (Zhang et al. 2005). Fifty-three elements fall into the
category of heavy metals to date, and heavy metals are defined as the group of
elements whose densities are higher than 5 g cm 3 and are recognized as environ-
mental contaminants in industrialized societies (Padmavathiamma and Li 2007).
Diffuse and point pollution of soils by heavy metals is a major environmental
problem worldwide (Kumpiene et al. 2006). In particular, soils could become
contaminated by the accumulation of heavy metals and metalloids through
emissions from the rapidly expanding industrial areas, mine tailings, disposal of
high metal wastes, leaded gasoline and paints, land application of fertilizers, animal
manures, sewage sludge, pesticides, wastewater irrigation, coal combustion
residues, spillage of petrochemicals, and atmospheric deposition (Khan et al.
2008; Zhang et al. 2010) (Fig. 10.1). One important effect of heavy metals in the
soil from anthropogenic sources is that they tend to be more mobile and bioavail-
able than those from pedogenic or lithogenic ones (Kaasalainen and Yli-Halla
2003). Soil pollution caused by metals is somewhat different from air or water
pollution, because heavy metals persist in soil much longer than in other
compartments of the biosphere (Lasat 2002). In general, soil heavy metal contami-
nation might pose direct or indirect risks to humans and the ecosystem through
ingestion or contact with contaminated soil, the food chain (soil–plant–human or

A. Branzini (*) • M.S. Zubillaga
Department of Fertility and Fertilizers, School of Agronomy, University of Buenos Aires,
Buenos Aires, Argentina
e-mail: branzini@agro.uba.ar

D.K. Gupta (ed.), Plant-Based Remediation Processes, Soil Biology 35, 177
DOI 10.1007/978-3-642-35564-6_10, # Springer-Verlag Berlin Heidelberg 2013