Conference Papers

The phenomenon which takes place in the phytoremediation process of soils polluted with heavy metals is very difficult to be understood, due to complexity of dynamics in rizosphere zone, An important parameter for analysis of metal quantity accumulated in plant tissue is the bioconcentration factor (BCF) and is calculated either for a part of the plant, or fot the whole plat using the formula: BCF soil-plant = Qm / Qs, (quantity of metal accumulated in plant, mg/kg d.m. ratio to total concentration of metal from soil mg/kg d. m.). Correlating the metal concentration from soil/plant with BCF shows that the studied plants have affinity for metals in the following order Zn>Mn>Cu. On the other hand, plants demonstrate tolerance to Fe presence of 50-60 mg/kg d. m. Its accumulation is restricted through a mechanism specific to plants on values of 102 times lower the the quantity in the soil. By using of volcanic tuff as amendments, level of metals accumulation in plants is changed.

Waste dumps from cooper exploitations represent massive storages of fine sandy material with concentration between 200 and 2100 mg Cu/kg d.m. and low content in nutrients. Installing a vegetative layer on the polluted terrain has the purpose to fix the sandy material against erosion and strong winds and to progressive discard the metals. The study point out the evolution of some selected species that present germination and development potential on indigenous volcanic tuff as is and pillared. From the competition of the sowing species Festuca arundinaceea, Lotus corniculatus, Medicago sativa and Trifolium arvense with weeds result a vegetal layer with an adaped species that cover 70% of the surface sowed in the first year ocf culture.