Innovative approach to contaminated soil phytoremediation: heavy metal phytoextraction using energy crops

Abstract

Land contamination is now recognised as a problem capable to affect ecosystems and human health in a range of different ways. Perception of soil as a vital natural element as well as an essential resource for human survival and development raises public awareness of soil contamination as an important environmental issue worldwide. It is reported that more than 10 million contaminated sites exist on our planet, with half of the sites contaminated with heavy metals (Khalid et al., 2017). If most of organic contaminants are easily biodegradable, heavy metals are highly resistant to either biologically or chemically induced degradation. Successful phytoextraction technology development as well as implementation requires comprehensive understanding about heavy metal mobility influencing factors, metal behaviour in soil-plant system and their transfer peculiarities from substrate to different plant parts. One of the most abundant sources for alternative energy is biomass. However, due to the shortage of arable lands energy cropping is enforced to compete with traditional agriculture. But exists another problem, that upper soil layer in many regions is contaminated with trace elements (e.g. Cd, Cu) as a consequence of intensive farming. Soils with exceeding threshold values for heavy metals are no longer proper for food and feedstock production. Combining traditional phytoextraction with energy cropping could help not only to reduce contamination incorporating plants, and also to use biomass for energy recovery. An interdisciplinary approach on phytoremediation of heavy metal contaminated land could extend the accessibility of arable land for energy cropping, also reveal new possibilities to reuse rest products of phytoremediation process.[...]