كفاءة نبات القرّاص Urtica dioica في معالجة تربة ملوّثة بالرّصاص والكادميوم

Abstract

This study dealt with evaluating the ability of Nettle Urtica dioica to accumulate cadmium and lead in order to determine its efficiency for use in phytoremediation, based on a pot-experiment

     The results indicated a significant effect of lead and cadmium concentrations in the soil on the reduction of fresh and dry root weights across all treatments compared to the control. Furthermore, a significant effect of total lead and total cadmium concentrations in the soil was observed on the content of both metals in the roots and shoots.

The nettle plants were able to accumulate cadmium in their roots in higher quantities than in their shoots, with root cadmium concentrations ranging from 12.5 to 64.93 mg/kg. This exceeded the normal range of cadmium in plants. The values for the Bioconcentration Factor (BCF) were ˃1, while the Bioaccumulation Coefficient (BAC) and Translocation Factor (TF) were ˂1. The Soil Extraction Yield (SEY%) values for cadmium were low, indicating that approximately one thousand nettle cultivations over a two-month period would be required to clean soil with a total cadmium concentration of up to 15 mg/kg, which is impractical. Collectively, these findings suggest that nettle is more successful as a phytostabilizer rather than a phytoextractor for cadmium-contaminated soils, helping to protect the biosphere from cadmium transfer, especially given that it is not grazed upon while green.

     Nettle plants did not demonstrate efficiency in lead extraction, as all phytoremediation efficiency coefficients for lead were less than one. The Soil Extraction Yield (SEY%) values for lead were very low within the specific physio-chemical properties of the soil used in this research.