Soil Contamination to Land Restoration

Remediation of contaminated soils is one of the most important environmental issues. Chemical soil degradation affects 12% of all degraded soils in the world, totalling 2 billions hectares. Soil contamination is not only a social and sanitary issue, but has also an economic concern, since it implies major costs related to decreasing productivity and monetary evaluation of the contaminated sites. Costs related to remediation of contaminated soils (particularly with heavy metals) are very high. Many of the organic substances contribute to contaminate ecosystems and are very poisonous to living organisms and to human health. Correspondingly, many metals, when present at high concentration in the environment, are critical or toxic to plants and animals, and may enter the food chain and therefore affect humans. In recent years, the interest of both public authorities and private companies towards innovative methodologies for decontamination and restoration of contaminated sites has been increasing. Phytoremediation is an emerging technology that holds great potential in cleaning up contaminants that: 1) are near the surface, 2) are relatively non-leachable, 3) pose little imminent risk to human health or the environment, and 4) cover large surface areas. Moreover, it is cost-effective in comparison to current technologies, and environmental friendly. Most of the available data, until now, has come from microcosm experiments; full scale experiments could help in assessing the feasibility of phytoremediation, and its effective contribution to clean-up contaminated soils. However, phytoremediation is not yet ready for full scale application, despite favourable initial cost projections, which indicate expansion of clean-up market to be likely within the next few years. Future research should address new highly efficient accumulator plants, and related cultivation technologies, and this research must account for the spatial and temporal variability of complex systems that include mixtures of contaminants and organisms. See more