LEAD PHYTOEXTRACTION. EXPERIMENTS IN GREENHOUSE PUBLISHEDIuliana Georgiana PLOPEANU, Eugenia GAMENŢ, M. DUMITRU, Vera CARABULEA, Nicoleta VRÎNCEANU, Mariana MARINESCU, Mihaela ULMANU
Soil contamination can destroy the delicate equilibria between physical, chemical and biological processes, which influences soil fertility. The effects of soil contamination with heavy metals are already found in many zones of the entire world. In recent years increase the number of research focusing on the study of soil pollution with heavy metals due to various anthropogenic sources. Phytoremediation by phytoextraction is an extraction process and accumulation of contaminants / pollutants in plant tissues considered hiperaccumulators , including roots and aerial part. This paper presents experiments in Greenhouse to establish the effect that it has lead and treatment with EDTA ( ethylene diamine acetic acid ) on the capacity of lead translocation in maize plants. There are presented two cycles of vegetation on a Cambic chernozem soil polluted with two concentrations of Pb ( 1000 mg Pb∙kg -1 , 2000 mg Pb∙kg -1 ) and different contents of EDTA. Treatment with EDTA on a chernozem loaded with 1000 mg Pb/kg soil ( experiment I) did not affect plant growth and soil reaction in a molar ratio EDTA/Pb between 0.2 and 0.3 . Lower concentrations of EDTA are not typical for phytoextraction and higher concentrations had negative effects on plants . Treatment with EDTA on a chernozem loaded with 2000 mg Pb/kg soil ( experiment I I ) did not affect plant growth and soil reaction molar ratio of EDTA/Pb = 0.1 . Higher concentrations of EDTA had negative affects plants and high soil acidification after cycle after cycle II. EDTA capacity to increase the lead solubility in soil (chernozem) in the phytoextraction process without negative effects on maize, can be implemented as a practical solution only low and moderate polluted soils with lead (total lead concentration <1000 mg Pb/kg) EDTA can be applied every two years in a concentration expressed in molar ratio EDTA/Lead between 0.2 and 0.3. Phytoextraction method is not suitable for soils heavily polluted with lead, with a total lead content >1100 mg Pb/kg.
soil pollution, lead, phytoextraction, Green House experiment.