POTENTIAL OF SOME PLANTS TO URANIUM UPTAKE FROM POLLUTED SOIL

Abstract

Soil contaminated by various activities including industrial, medical, researches, agricultural, nuclear and non-nuclear activities. Phosphate fertilizers are an essential component of the agricultural activities that help increasing the crop production and improving the properties of the nutrient-deficient lands. However, a possible negative consequence of phosphate fertilizers is the contamination of cultivated lands by heavy metals, uranium and some naturally occurring radioactive materials. Phytoremediation has been developed as an economically and environmentally attractive approach to clean up heavy metal-polluted soils and restore the soil quality. One of the phytoremediation techniques, the so-called phytoextraction, relies on using of some plants to extract metals from the soil and translocate them to the shoots. The aim of phytoextraction is to reduce the concentration of metals in the contaminated soils to regulatory levels within a reasonable time frame. Two approaches have currently been proposed to reach such goal: using of plants of exceptionally high natural metal-accumulating capacity named hyperaccumulators and utilization of high-biomass crop plants in association with a chemically enhanced method of phytoextraction. The plan of this study was proposed to decontaminate the polluted soil with uranium and some heavy metals employing the phytoremediation technique. Thus, two known hyperaccumulators plants (indian mustard and ryegrass) were utilized and enhanced their uptake efficiency using some low molecular weight organic acids (LMWOA) and chelate agent (citric acid, oxalic acid and EDTA). Accordingly, two pot experiments were set up during 2014/2015 and 2015/2016 seasons in the greenhouse of Nuclear Materials Authority (NMA) to investigate the ability of citric acid C6H8O7 (CA), oxalic acid H2C2O4.2H2O (OA) and Ethylenediaminetetraacetic acid ( EDTA) on