Phytotechnologies exploit natural plant physiological and biochemical processes, and green plants can be used for decontamination of soils polluted with trace elements and organic compounds (phytoremediation). A significant part of agricultural land in Europe and elsewhere is contaminated with heavy metals, some of which still in agriculture use. Plants play a crucial role in the contamination of the food chain by toxic metals, via primary accumulation before entry into animal or human body. Nowadays, the use of plants for the removal of atmospheric contaminants is less developed, but it will become extremely relevant to sustainable development and human health. Phytoextraction can be considered absorption of trace elements into roots, then translocation into shoots, followed by the harvest and destruction of the contaminated plants, with possible recycling strategies to recover metals from biomass or ash. The paper presents the preliminary tests regarding the remanent effect of Pb and EDTA treatment on the capacity of lead translocation into maize plants. It is presented the second vegetation cycle of maize plants on cambic chernozem soil material treated with both three different lead concentrations (1000 mgPb·kg-1, 2000 mgPb·kg-1, 300 0mgPb·kg-1) and EDTA remanent contents. The treatments (Pb and EDTA) were applied before seeding, at the beginning of the cicle I and consisted in the application of three lead concentrations (1000 mgPb·kg-1, 2000 mgPb·kg-1, 3000 mgPb·kg-1) and 6 concentrations levels of EDTA (expressed as ratio between EDTA and Pb). To study the remanent effect, we limited the number of doses of EDTA to 4 concentrations (0; 0.5; 1; 2). Similar with the first cycle, the plants weight, the plants height and the lead content from maize shoots are strongly influenced by the treatments with Pb, EDTA or Pb+EDTA. Pb concentration in biomass increased with EDTA concentration for the same Pb pollution degree. This study, as a preliminary test, evaluated the maximum permissible levels as concern both the lead accumulation degree and the chelating agent concentrations required to perform some phytoextraction conditions.

phytoextraction; soil pollution; Pb; EDTA; remanent effect

Presentation: oral